796 lines
No EOL
65 KiB
Text
796 lines
No EOL
65 KiB
Text
<!doctype html>
|
||
|
||
<html lang="en-US">
|
||
|
||
<head>
|
||
<meta charset="utf-8">
|
||
<meta name="viewport" content="width=device-width, initial-scale=1.0">
|
||
<meta http-equiv="X-UA-Compatible" content="IE=edge">
|
||
<title>The A1C Test & Diabetes - NIDDK</title>
|
||
|
||
<meta name="msvalidate.01" content="7FEF9D64C9916EC9393EB5B21BD0037E">
|
||
|
||
<meta name="format-detection" content="telephone=no">
|
||
<link rel="icon" href="/_ux/niddk/9.37.0/favicon.ico">
|
||
<link rel="apple-touch-icon" href="/_ux/niddk/9.37.0/images/apple-touch-icon.png">
|
||
|
||
<link rel="preconnect" href="https://www.google-analytics.com">
|
||
<link rel="preconnect" href="https://www.googletagmanager.com">
|
||
<link rel="dns-prefetch" href="https://www.google-analytics.com">
|
||
<link rel="dns-prefetch" href="https://www.googletagmanager.com">
|
||
<link rel="dns-prefetch" href="https://dap.digitalgov.gov">
|
||
<link rel="dns-prefetch" href="https://livechat.niddk.nih.gov">
|
||
<link rel="preload" as="font" type="font/woff2" href="/_ux/niddk/9.37.0/styles/fonts/merriweather-v30-latin-regular.woff2" crossorigin>
|
||
<link rel="preload" as="font" type="font/woff2" href="/_ux/niddk/9.37.0/styles/fonts/open-sans-v29-latin-regular.woff2" crossorigin>
|
||
<link rel="preload" as="font" type="font/woff2" href="/_ux/niddk/9.37.0/styles/fonts/open-sans-v29-latin-600.woff2" crossorigin>
|
||
<link rel="preload" as="font" type="font/woff2" href="/_ux/niddk/9.37.0/styles/fonts/open-sans-v29-latin-700.woff2" crossorigin>
|
||
<link rel="preload" as="font" type="font/woff2" href="/_ux/niddk/9.37.0/styles/fonts/montserrat-v24-latin-regular.woff2" crossorigin>
|
||
<link rel="preload" as="font" type="font/woff2" href="/_ux/niddk/9.37.0/styles/fonts/dki.woff2" crossorigin>
|
||
|
||
<link rel="preload" as="fetch" href="/_internal/livechat/livechatstatus?id=c2c6c0d2-b886-4b44-aaf2-26bf2a8c1783" id="_lcstatuslink" crossorigin>
|
||
|
||
<link rel="stylesheet" media="print" onload="this.media='all'" href="/_ux/niddk/9.37.0/deps/slick-carousel/slick.min.css">
|
||
<link rel="stylesheet" media="print" onload="this.media='all'" href="/_ux/niddk/9.37.0/deps/jquery-scrolltabs/scrolltabs.min.css">
|
||
<link rel="stylesheet" media="print" onload="this.media='all'" href="/_ux/niddk/9.37.0/deps/magnific-popup/magnific-popup.min.css">
|
||
<link rel="stylesheet" media="print" onload="this.media='all'" href="/_ux/niddk/9.37.0/deps/tablesaw/tablesaw.min.css">
|
||
|
||
<link rel="stylesheet" href="/_ux/niddk/9.37.0/styles/niddk-web.css">
|
||
<noscript><link rel="stylesheet" href="/_ux/niddk/9.37.0/styles/niddk-nojs.css"></noscript>
|
||
|
||
|
||
|
||
<link href="https://www.niddk.nih.gov/health-information/diagnostic-tests/a1c-test" rel="canonical" />
|
||
<meta name="description" content="Learn what the A1C test is, how it works and is used to diagnose and monitor type 2 diabetes and prediabetes, when it doesn’t work, and how A1C relates to eAG." />
|
||
<meta name="keywords" content="A1C, hemoglobin A1C, HbA1C, glycohemoglobin test, glycated hemoglobin, diagnosis, management, diabetes, prediabetes, testing, eAG, estimated average glucose, blood tests" />
|
||
<meta property="og:url" content="https://www.niddk.nih.gov/health-information/diagnostic-tests/a1c-test">
|
||
<meta property="og:type" content="article" />
|
||
<meta property="og:title" content="The A1C Test & Diabetes - NIDDK" />
|
||
<meta property="og:description" content="Learn what the A1C test is, how it works and is used to diagnose and monitor type 2 diabetes and prediabetes, when it doesn’t work, and how A1C relates to eAG." />
|
||
<meta property="og:image" content="https://www.niddk.nih.gov/-/media/Images/Components/Default-Social-Media-Images/Health-Information-Card-ALT3.png" />
|
||
<meta property="og:site_name" content="National Institute of Diabetes and Digestive and Kidney Diseases" />
|
||
<meta name="twitter:card" content="summary" />
|
||
<meta name="twitter:site:id" content="1901405066" />
|
||
<meta name="twitter:title" content="The A1C Test & Diabetes - NIDDK" />
|
||
<meta name="twitter:description" content="Learn what the A1C test is, how it works and is used to diagnose and monitor type 2 diabetes and prediabetes, when it doesn’t work, and how A1C relates to eAG." />
|
||
<meta name="twitter:image" content="https://www.niddk.nih.gov/-/media/Images/Components/Default-Social-Media-Images/Health-Information-Card-ALT3.png" />
|
||
<script>
|
||
window.dataLayer = window.dataLayer || [];
|
||
dataLayer.push({"pageID":"c2c6c0d2-b886-4b44-aaf2-26bf2a8c1783","topicID":"0163","topicName":"A1C Test & Diabetes","pagePath":"/health-information/diagnostic-tests/a1c-test","pageTitle":"The A1C Test & Diabetes","pageDiseaseArea":"Diabetes","pageLanguage":"English","pageAudience":"Patients","lastReviewedDate":"2018-04-20"});
|
||
</script>
|
||
<script type="application/ld+json">
|
||
{
|
||
"@context": "https://schema.org",
|
||
"@type": "Article",
|
||
"headline": "The A1C Test &amp; Diabetes",
|
||
"description": "Learn what the A1C test is, how it works and is used to diagnose and monitor type 2 diabetes and prediabetes, when it doesn’t work, and how A1C relates to eAG.",
|
||
"url": "https://www.niddk.nih.gov/health-information/diagnostic-tests/a1c-test",
|
||
"datePublished": "2025-01-08 21:05:04 -05:00",
|
||
"dateModified": "2025-01-08 21:05:04 -05:00",
|
||
"publisher": {
|
||
"@type": "Organization",
|
||
"name": "NIDDK - National Institute of Diabetes and Digestive and Kidney Diseases",
|
||
"logo": {
|
||
"@type": "ImageObject",
|
||
"url": "https://www.niddk.nih.gov/-/media/Images/Components/common/site-logo-full.svg"
|
||
}
|
||
}
|
||
}
|
||
</script>
|
||
|
||
|
||
|
||
|
||
<script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
|
||
new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
|
||
j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
|
||
'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
|
||
})(window,document,'script','dataLayer','GTM-MBRL4D');</script></head>
|
||
<body itemscope itemtype="http://schema.org/MedicalWebPage" class="page-lang-en">
|
||
<noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-MBRL4D" height="0" width="0" style="display:none;visibility:hidden" name="Google Tag Manager" title="Google Tag Manager"></iframe></noscript>
|
||
<div class="site-wrap">
|
||
<header class="site-header">
|
||
<a href="#main" class="skip-link">Skip to main content</a>
|
||
<div class="site-alerts">
|
||
|
||
</div>
|
||
<section class="usa-banner" aria-label="Official website of the United States government">
|
||
<div class="usa-accordion grid">
|
||
<div class="usa-banner__header">
|
||
<div class="usa-banner__inner">
|
||
<div class="usa-banner__inner-flag">
|
||
<img class="usa-banner__header-flag" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAALCAMAAABBPP0LAAAAG1BMVEUdM7EeNLIeM7HgQCDaPh/bPh/bPx/////bPyBEby41AAAAUElEQVQI123MNw4CABDEwD3jC/9/MQ1BQrgeOSkIqYe2o2FZtthXgQLgbHVMZdlsfUQFQnHtjP1+8BUhBDKOqtmfot6ojqPzR7TjdU+f6vkED+IDPhTBcMAAAAAASUVORK5CYII=" alt="U.S. flag">
|
||
</div>
|
||
<div class="usa-banner__inner-text">
|
||
<p class="usa-banner__header-text">An official website of the United States government</p>
|
||
<p class="usa-banner__header-action" aria-hidden="true">Here’s how you know</p>
|
||
</div>
|
||
<button type="button" class="usa-banner__button" aria-expanded="false" aria-controls="gov-banner">
|
||
<span class="usa-banner__button-text">Here’s how you know</span>
|
||
</button>
|
||
</div>
|
||
</div>
|
||
<div class="usa-banner__content usa-accordion__content" id="gov-banner" hidden>
|
||
<div class="usa-banner__guidance">
|
||
<svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" width="64" height="64" viewBox="0 0 64 64"><title>Official government website icon</title><path fill="#2378C3" fill-rule="evenodd" d="M32 0c17.673 0 32 14.327 32 32 0 17.673-14.327 32-32 32C14.327 64 0 49.673 0 32 0 14.327 14.327 0 32 0zm0 1.208C14.994 1.208 1.208 14.994 1.208 32S14.994 62.792 32 62.792 62.792 49.006 62.792 32 49.006 1.208 32 1.208zm10.59 38.858a.857.857 0 0 1 .882.822v1.642H18.886v-1.642a.857.857 0 0 1 .882-.822H42.59zM25.443 27.774v9.829h1.642v-9.83h3.273v9.83H32v-9.83h3.272v9.83h1.643v-9.83h3.272v9.83h.76a.857.857 0 0 1 .882.821v.821h-21.3v-.809a.857.857 0 0 1 .88-.82h.762v-9.842h3.272zm5.736-8.188l12.293 4.915v1.642h-1.63a.857.857 0 0 1-.882.822H21.41a.857.857 0 0 1-.882-.822h-1.642v-1.642l12.293-4.915z" /></svg>
|
||
<div class="usa-media-block__body">
|
||
<p>
|
||
<strong>Official websites use .gov</strong>
|
||
<br>
|
||
A <strong>.gov</strong> website belongs to an official government organization in the United States.
|
||
</p>
|
||
</div>
|
||
</div>
|
||
<div class="usa-banner__guidance">
|
||
<svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" width="64" height="64" viewBox="0 0 64 64"><title>icon-https</title><path fill="#719F2A" fill-rule="evenodd" d="M32 0c17.673 0 32 14.327 32 32 0 17.673-14.327 32-32 32C14.327 64 0 49.673 0 32 0 14.327 14.327 0 32 0zm0 1.208C14.994 1.208 1.208 14.994 1.208 32S14.994 62.792 32 62.792 62.792 49.006 62.792 32 49.006 1.208 32 1.208zm0 18.886a7.245 7.245 0 0 1 7.245 7.245v3.103h.52c.86 0 1.557.698 1.557 1.558v9.322c0 .86-.697 1.558-1.557 1.558h-15.53c-.86 0-1.557-.697-1.557-1.558V32c0-.86.697-1.558 1.557-1.558h.52V27.34A7.245 7.245 0 0 1 32 20.094zm0 3.103a4.142 4.142 0 0 0-4.142 4.142v3.103h8.284V27.34A4.142 4.142 0 0 0 32 23.197z" /></svg>
|
||
<div class="usa-media-block__body">
|
||
<p>
|
||
<strong>Secure .gov websites use HTTPS</strong>
|
||
<br>
|
||
A <strong>lock</strong> (
|
||
<span class="icon-lock">
|
||
<svg xmlns="http://www.w3.org/2000/svg" width="52" height="64" viewbox="0 0 52 64" class="usa-banner__lock-image" role="img" aria-labelledby="banner-lock-title banner-lock-description" focusable="false">
|
||
<title id="banner-lock-title">Lock</title>
|
||
<desc id="banner-lock-description">Locked padlock icon</desc>
|
||
<path fill="#000000" fill-rule="evenodd" d="M26 0c10.493 0 19 8.507 19 19v9h3a4 4 0 0 1 4 4v28a4 4 0 0 1-4 4H4a4 4 0 0 1-4-4V32a4 4 0 0 1 4-4h3v-9C7 8.507 15.507 0 26 0zm0 8c-5.979 0-10.843 4.77-10.996 10.712L15 19v9h22v-9c0-6.075-4.925-11-11-11z" />
|
||
</svg>
|
||
</span>
|
||
) or <strong>https://</strong> means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
|
||
</p>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</section>
|
||
<div class="stripe-brand">
|
||
<div class="dk-brand-wrap">
|
||
<div class="dk-site-logos">
|
||
<a href="/" title="NIDDK home page">
|
||
<img src="/_ux/niddk/9.37.0/images/site-logos.svg#full" width="300" height="67" class="desktop" alt="NIH: National Institute of Diabetes and Digestive and Kidney Diseases" />
|
||
<img src="/_ux/niddk/9.37.0/images/site-logos.svg#abbrev" width="150" height="34" class="mobile" alt="NIH: National Institute of Diabetes and Digestive and Kidney Diseases" />
|
||
</a>
|
||
<a href="/about-niddk/75th-anniversary" title="NIDDK 75th Anniversary">
|
||
<img src="/_ux/niddk/9.37.0/images/site-logos.svg#full75" width="63" height="67" class="desktop" alt="75 years: 1950-2025" />
|
||
<img src="/_ux/niddk/9.37.0/images/site-logos.svg#abbrev75" width="35" height="30" class="mobile" alt="75 years: 1950-2025" />
|
||
</a>
|
||
</div>
|
||
<div class="dk-site-mobile-toolbar">
|
||
<button type="button" class="mobile-site-search"><i class="i-search"></i>Search</button>
|
||
<button type="button" class="dk-nav-menu"><i class="i-menu"></i>Menu</button>
|
||
</div>
|
||
|
||
<form class="dk-site-search" id="site-search" action="/search" method="GET" aria-label="Site search">
|
||
<button type="button" class="close-mobile-site-search" aria-label="Close search"><i class="i-times"></i></button>
|
||
<div class="site-search-info">Search for Information from NIDDK</div>
|
||
<button type="button" class="ss-options" title="Change search scope" aria-label="Select scope" aria-haspopup="true" aria-owns="site-search-opts">
|
||
<i class="i-angle-down" aria-hidden="true"></i>
|
||
</button>
|
||
<ul id="site-search-opts" role="menu" aria-hidden="true" aria-label="Scope options">
|
||
<li role="menuitemradio" aria-checked="true" data-value="all">Entire Site</li>
|
||
<li role="menuitemradio" aria-checked="false" data-value="research">Research & Funding</li>
|
||
<li role="menuitemradio" aria-checked="false" data-value="health-info">Health Information</li>
|
||
<li role="menuitemradio" aria-checked="false" data-value="news">News</li>
|
||
<li role="menuitemradio" aria-checked="false" data-value="about">About NIDDK</li>
|
||
</ul>
|
||
<input type="hidden" name="s" value="all" />
|
||
<input type="text" name="q" placeholder="Search Entire Site…" aria-label="Site search terms" />
|
||
<button type="submit" class="ss-go" title="Search Entire Site">Search</button>
|
||
</form>
|
||
</div>
|
||
</div>
|
||
|
||
<nav class="dk-site-nav sticky" aria-label="Site">
|
||
<div class="grid" role="presentation">
|
||
<div class="sn-bar" role="list" aria-owns="dk_sn0 dk_sn1 dk_sn2 dk_sn3 dk_sn4">
|
||
<div id="dk_sn0" class="sn-home" role="listitem">
|
||
<div class="sn-section-title">
|
||
<a href="/" class="dk-logo">Home</a>
|
||
</div>
|
||
</div>
|
||
<div class="sn-sections-wrap" role="presentation">
|
||
<div class="sn-sections" role="presentation">
|
||
<div id="dk_sn1" class="sn-section" role="listitem">
|
||
<input id="dk_snexpand1" type="checkbox" class="sn-chk-expand"/>
|
||
<div class="sn-section-title">
|
||
<a href="/research-funding"><span>Research & Funding</span></a>
|
||
<label for="dk_snexpand1" class="sn-lbl-expand">Expand Research & Funding</label>
|
||
</div>
|
||
<div class="sn-subsections" role="list">
|
||
<div class="sn-collapsible">
|
||
<div role="presentation">
|
||
<div role="listitem"><a href="/research-funding/current-opportunities">Current Funding Opportunities</a></div>
|
||
<div role="listitem"><a href="/research-funding/research-programs">Research Programs & Contacts</a></div>
|
||
<div role="listitem"><a href="/research-funding/human-subjects-research">Human Subjects Research</a></div>
|
||
<div role="listitem"><a href="/research-funding/process">Funding Process</a></div>
|
||
</div>
|
||
<div role="presentation">
|
||
<div role="listitem"><a href="/research-funding/training-career-development">Research Training & Career Development</a></div>
|
||
<div role="listitem"><a href="/research-funding/funded-grants-grant-history">Funded Grants & Grant History</a></div>
|
||
<div role="listitem"><a href="/research-funding/research-resources">Research Resources</a></div>
|
||
</div>
|
||
<div role="presentation">
|
||
<div role="listitem"><a href="/research-funding/at-niddk">Research at NIDDK</a></div>
|
||
<div role="listitem"><a href="/research-funding/technology-advancement-transfer">Technology Advancement & Transfer</a></div>
|
||
<div role="listitem"><a href="/news/meetings-workshops">Meetings & Workshops</a></div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
<div id="dk_sn2" class="sn-section current" role="listitem">
|
||
<input id="dk_snexpand2" type="checkbox" class="sn-chk-expand"/>
|
||
<div class="sn-section-title">
|
||
<a href="/health-information"><span>Health Information</span></a>
|
||
<label for="dk_snexpand2" class="sn-lbl-expand">Expand Health Information</label>
|
||
</div>
|
||
<div class="sn-subsections" role="list">
|
||
<div class="sn-collapsible">
|
||
<div role="group" class="sn-subgroup" aria-labelledby="dk_snsg0">
|
||
<div id="dk_snsg0" class="sn-subgroup-title" role="presentation">Health Topics</div>
|
||
<div role="listitem"><a href="/health-information/diabetes">Diabetes</a></div>
|
||
<div role="listitem"><a href="/health-information/digestive-diseases">Digestive Diseases</a></div>
|
||
<div role="listitem"><a href="/health-information/kidney-disease">Kidney Disease</a></div>
|
||
<div role="listitem"><a href="/health-information/weight-management">Weight Management</a></div>
|
||
<div role="listitem"><a href="/health-information/liver-disease">Liver Disease</a></div>
|
||
<div role="listitem"><a href="/health-information/urologic-diseases">Urologic Diseases</a></div>
|
||
<div role="listitem"><a href="/health-information/endocrine-diseases">Endocrine Diseases</a></div>
|
||
<div role="listitem"><a href="/health-information/diet-nutrition">Diet & Nutrition</a></div>
|
||
<div role="listitem"><a href="/health-information/blood-diseases">Blood Diseases</a></div>
|
||
<div role="listitem"><a href="/health-information/diagnostic-tests">Diagnostic Tests</a></div>
|
||
</div>
|
||
<div role="presentation">
|
||
<div role="listitem"><a href="/health-information/informacion-de-la-salud">La información de la salud en español</a></div>
|
||
<div role="listitem"><a href="/health-information/health-statistics">Health Statistics</a></div>
|
||
<div role="listitem"><a href="/health-information/clinical-trials">Clinical Trials</a></div>
|
||
</div>
|
||
<div role="presentation">
|
||
<div role="listitem"><a href="/health-information/professionals">For Health Professionals</a></div>
|
||
<div role="listitem"><a href="/health-information/professionals/diabetes-discoveries-practice">Diabetes Discoveries & Practice Blog</a></div>
|
||
<div role="listitem"><a href="/health-information/community-health-outreach">Community Health & Outreach</a></div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
<div id="dk_sn3" class="sn-section" role="listitem">
|
||
<input id="dk_snexpand3" type="checkbox" class="sn-chk-expand"/>
|
||
<div class="sn-section-title">
|
||
<a href="/news"><span>News</span></a>
|
||
<label for="dk_snexpand3" class="sn-lbl-expand">Expand News</label>
|
||
</div>
|
||
<div class="sn-subsections" role="list">
|
||
<div class="sn-collapsible">
|
||
<div role="presentation">
|
||
<div role="listitem"><a href="/news/archive">News Archive</a></div>
|
||
<div role="listitem"><a href="/news/for-reporters">For Reporters</a></div>
|
||
</div>
|
||
<div role="presentation">
|
||
<div role="listitem"><a href="/news/meetings-workshops">Meetings & Workshops</a></div>
|
||
<div role="listitem"><a href="/news/media-library">Media Library</a></div>
|
||
</div>
|
||
<div role="presentation">
|
||
<div role="listitem"><a href="/news/follow-us">Follow Us</a></div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
<div id="dk_sn4" class="sn-section" role="listitem">
|
||
<input id="dk_snexpand4" type="checkbox" class="sn-chk-expand"/>
|
||
<div class="sn-section-title">
|
||
<a href="/about-niddk"><span>About NIDDK</span></a>
|
||
<label for="dk_snexpand4" class="sn-lbl-expand">Expand About NIDDK</label>
|
||
</div>
|
||
<div class="sn-subsections" role="list">
|
||
<div class="sn-collapsible">
|
||
<div role="presentation">
|
||
<div role="listitem"><a href="/about-niddk/meet-director">Meet the Director</a></div>
|
||
<div role="listitem"><a href="/about-niddk/offices-divisions">Offices & Divisions</a></div>
|
||
<div role="listitem"><a href="/about-niddk/staff-directory">Staff Directory</a></div>
|
||
<div role="listitem"><a href="/about-niddk/budget-legislative-information">Budget & Legislative Information</a></div>
|
||
</div>
|
||
<div role="presentation">
|
||
<div role="listitem"><a href="/about-niddk/advisory-coordinating-committees">Advisory & Coordinating Committees</a></div>
|
||
<div role="listitem"><a href="/about-niddk/strategic-plans-reports">Strategic Plans & Reports</a></div>
|
||
<div role="listitem"><a href="/about-niddk/research-areas">Research Areas</a></div>
|
||
<div role="listitem"><a href="/about-niddk/faqs">FAQs</a></div>
|
||
</div>
|
||
<div role="presentation">
|
||
<div role="listitem"><a href="/about-niddk/jobs">Jobs at NIDDK</a></div>
|
||
<div role="listitem"><a href="/about-niddk/visit-us">Visit Us</a></div>
|
||
<div role="listitem"><a href="/about-niddk/contact-us">Contact Us</a></div>
|
||
<div role="listitem"><a href="/about-niddk/75th-anniversary">NIDDK 75th Anniversary</a></div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</nav>
|
||
<div class="balloon"></div>
|
||
|
||
</header>
|
||
<main id="main">
|
||
<div class="grid dk-two-column">
|
||
<div class="dk-breadcrumb-row">
|
||
<script type="application/ld+json">
|
||
{
|
||
"@context": "https://schema.org",
|
||
"@type": "BreadcrumbList",
|
||
"itemListElement" : [
|
||
|
||
{
|
||
"@type": "ListItem",
|
||
"position": 1,
|
||
"name": "Home",
|
||
|
||
"item": "https://www.niddk.nih.gov"
|
||
},
|
||
|
||
|
||
{
|
||
"@type": "ListItem",
|
||
"position": 2,
|
||
"name": "Health Information",
|
||
|
||
"item": "https://www.niddk.nih.gov/health-information"
|
||
},
|
||
|
||
|
||
{
|
||
"@type": "ListItem",
|
||
"position": 3,
|
||
"name": "Diagnostic Tests",
|
||
|
||
"item": "https://www.niddk.nih.gov/health-information/diagnostic-tests"
|
||
},
|
||
|
||
|
||
{
|
||
"@type": "ListItem",
|
||
"position": 4,
|
||
"name": "A1C Test & Diabetes"
|
||
|
||
}
|
||
|
||
]
|
||
}
|
||
</script>
|
||
<div class="dk-breadcrumbs">
|
||
<ol>
|
||
<li>
|
||
|
||
<a href="/"><span>Home</span></a>
|
||
</li>
|
||
<li>
|
||
|
||
<a href="/health-information"><span>Health Information</span></a>
|
||
</li>
|
||
<li>
|
||
|
||
<a href="/health-information/diagnostic-tests"><span>Diagnostic Tests</span></a>
|
||
</li>
|
||
<li>
|
||
<span>A1C Test & Diabetes</span>
|
||
</li>
|
||
</ol>
|
||
</div>
|
||
|
||
<button type="button" class="context-menu-button">Related Topics</button>
|
||
<div class="dk-language-dropdown">
|
||
<button type="button" name="options" title="Show alternate languages for this page" aria-label="Alternate languages" aria-haspopup="true" aria-owns="language-picker-opts">
|
||
<span class="language">English</span>
|
||
</button>
|
||
<ul id="language-picker-opts" role="menu" aria-hidden="true">
|
||
<li role="menuitem" class="current"><a href="/health-information/diagnostic-tests/a1c-test">English</a></li>
|
||
<li role="menuitem"><a href="/health-information/informacion-de-la-salud/pruebas-diagnosticas/prueba-a1c-diabetes">Español</a></li>
|
||
</ul>
|
||
</div>
|
||
|
||
</div>
|
||
<div class="dk-main-container">
|
||
<nav class="dk-leftnav" aria-label="Section navigation">
|
||
|
||
|
||
|
||
<a href="/health-information/diagnostic-tests" aria-description="Parent page">Diagnostic Tests</a>
|
||
<ul>
|
||
|
||
<li class="ln-current">
|
||
<span>A1C Test & Diabetes</span>
|
||
</li>
|
||
<li class="ln-collapsed">
|
||
<a href="/health-information/diagnostic-tests/a1c-test-race-ethnicity">A1C Test & Race/Ethnicity</a>
|
||
</li>
|
||
<li class="ln-collapsed">
|
||
<a href="/health-information/diagnostic-tests/colonoscopy">Colonoscopy</a>
|
||
</li>
|
||
<li class="ln-collapsed">
|
||
<a href="/health-information/diagnostic-tests/cystoscopy-ureteroscopy">Cystoscopy & Ureteroscopy</a>
|
||
</li>
|
||
<li class="ln-collapsed">
|
||
<a href="/health-information/diagnostic-tests/endoscopic-retrograde-cholangiopancreatography">Endoscopic Retrograde Cholangiopancreatography (ERCP)</a>
|
||
</li>
|
||
<li class="ln-collapsed">
|
||
<a href="/health-information/diagnostic-tests/flexible-sigmoidoscopy">Flexible Sigmoidoscopy</a>
|
||
</li>
|
||
<li class="ln-collapsed">
|
||
<a href="/health-information/diagnostic-tests/kidney-biopsy">Kidney Biopsy</a>
|
||
</li>
|
||
<li class="ln-collapsed">
|
||
<a href="/health-information/diagnostic-tests/liver-biopsy">Liver Biopsy</a>
|
||
</li>
|
||
<li class="ln-collapsed">
|
||
<a href="/health-information/diagnostic-tests/lower-gi-series">Lower GI Series</a>
|
||
</li>
|
||
<li class="ln-collapsed">
|
||
<a href="/health-information/diagnostic-tests/prostate">Prostate Tests</a>
|
||
</li>
|
||
<li class="ln-collapsed">
|
||
<a href="/health-information/diagnostic-tests/thyroid">Thyroid Tests</a>
|
||
</li>
|
||
<li class="ln-collapsed">
|
||
<a href="/health-information/diagnostic-tests/upper-gi-endoscopy">Upper GI Endoscopy</a>
|
||
</li>
|
||
<li class="ln-collapsed">
|
||
<a href="/health-information/diagnostic-tests/upper-gi-series">Upper GI Series</a>
|
||
</li>
|
||
<li class="ln-collapsed">
|
||
<a href="/health-information/diagnostic-tests/urinary-tract-imaging">Urinary Tract Imaging</a>
|
||
</li>
|
||
<li class="ln-collapsed">
|
||
<a href="/health-information/diagnostic-tests/urodynamic-testing">Urodynamic Testing</a>
|
||
</li>
|
||
<li class="ln-collapsed">
|
||
<a href="/health-information/diagnostic-tests/virtual-colonoscopy">Virtual Colonoscopy</a>
|
||
</li>
|
||
</ul>
|
||
|
||
</nav>
|
||
<article class="dk-content">
|
||
<h1 itemprop="name">The A1C Test & Diabetes</h1>
|
||
<div class="health-detail-content">
|
||
|
||
<p><strong>On this page:</strong></p>
|
||
<ul>
|
||
<li><a href="#whatis">What is the A1C test?</a></li>
|
||
<li><a href="#why">Why should a person get the A1C test?</a></li>
|
||
<li><a href="#diagnose">How is the A1C test used to diagnose type 2 diabetes and prediabetes? </a></li>
|
||
<li><a href="#pregnancy">Is the A1C test used during pregnancy?</a></li>
|
||
<li><a href="#other">Can other blood glucose tests be used to diagnose type 2 diabetes and prediabetes?</a></li>
|
||
<li><a href="#different">Can the A1C test result in a different diagnosis than the blood glucose tests?</a></li>
|
||
<li><a href="#vary">Why do diabetes blood test results vary?</a></li>
|
||
<li><a href="#precise">How precise is the A1C test?</a></li>
|
||
<li><a href="#after">How is the A1C test used after diagnosis of diabetes?</a></li>
|
||
<li><a href="#goal">What A1C goal should I have?</a></li>
|
||
<li><a href="#glucose">How does A1C relate to estimated average glucose?</a></li>
|
||
<li><a href="#changes">Will the A1C test show short-term changes in blood glucose levels?</a></li>
|
||
<li><a href="#clinicaltrials">Clinical Trials for the A1C Test and Diabetes</a></li>
|
||
</ul>
|
||
<h2 id="whatis">What is the A1C test?</h2>
|
||
<p>The A1C test is a blood test that provides information about your average levels of blood glucose, also called blood sugar, over the past 3 months. The A1C test can be used to diagnose <a href="/health-information/diabetes/overview/what-is-diabetes/type-2-diabetes">type 2 diabetes</a> and <a href="/health-information/diabetes/overview/what-is-diabetes/prediabetes-insulin-resistance">prediabetes</a>.<sup>1</sup> The A1C test is also the primary test used for <a href="/health-information/diabetes/overview/managing-diabetes">diabetes management</a>.</p>
|
||
<figure class="small center">
|
||
<img alt="A health care professional draws blood." src="/-/media/Images/Health-Information/Diabetes/HCP_drawingblood_330x220.png" />
|
||
<figcaption>An A1C test is a blood test that reflects your average blood glucose levels over the past 3 months.</figcaption>
|
||
</figure>
|
||
<p>The A1C test is sometimes called the hemoglobin A1C, HbA1c, glycated hemoglobin, or glycohemoglobin test. Hemoglobin is the part of a red blood cell that carries oxygen to the cells. Glucose attaches to or binds with hemoglobin in your blood cells, and the A1C test is based on this attachment of glucose to hemoglobin.</p>
|
||
<p>The higher the glucose level in your bloodstream, the more glucose will attach to the hemoglobin. The A1C test measures the amount of hemoglobin with attached glucose and reflects your average blood glucose levels over the past 3 months.</p>
|
||
<p>The A1C test result is reported as a percentage. The higher the percentage, the higher your blood glucose levels have been. A normal A1C level is below 5.7 percent.</p>
|
||
<h2 id="why">Why should a person get the A1C test?</h2>
|
||
<p>Testing can help health care professionals</p>
|
||
<ul>
|
||
<li>find prediabetes and counsel you about lifestyle changes to help you delay or <a href="/health-information/diabetes/overview/preventing-type-2-diabetes">prevent type 2 diabetes</a></li>
|
||
<li>find type 2 diabetes</li>
|
||
<li>work with you to monitor the disease and help make treatment decisions to prevent <a class="dictionary-term" href="/Dictionary/C/complications">complications</a></li>
|
||
</ul>
|
||
<p>If you have <a href="/health-information/diabetes/overview/risk-factors-type-2-diabetes">risk factors for prediabetes or diabetes</a>, talk with your doctor about whether you should be tested.</p>
|
||
<figure class="small center">
|
||
<img alt="Couple walking with their dog." src="/-/media/Images/Health-Information/Diabetes/CoupleWalking_330x221.png" />
|
||
<figcaption>You may be able to prevent or delay type 2 diabetes with lifestyle changes such as weight loss or being physically active most days of the week.</figcaption>
|
||
</figure>
|
||
<h2 id="diagnose">How is the A1C test used to diagnose type 2 diabetes and prediabetes?</h2>
|
||
<p>Health care professionals can use the A1C test alone or in combination with <a href="/health-information/diabetes/overview/tests-diagnosis">other diabetes tests</a> to diagnose type 2 diabetes and prediabetes. You don’t have to <a class="dictionary-term" href="/Dictionary/F/fast">fast</a> before having your blood drawn for an A1C test, which means that blood can be drawn for the test at any time of the day.</p>
|
||
<p>If you don’t have symptoms but the A1C test shows you have diabetes or prediabetes, you should have a repeat test on a different day using the A1C test or one of the other diabetes tests to confirm the diagnosis.<sup>2</sup></p>
|
||
<h3>A1C results and what the numbers mean</h3>
|
||
<table class="tablesaw-swipe" id="table-5686" data-tablesaw-mode="swipe">
|
||
<caption>*Any test used to diagnose diabetes requires confirmation with a second measurement, unless there are clear symptoms of diabetes.</caption>
|
||
<thead>
|
||
<tr>
|
||
<th class="tablesaw-cell-persist" data-tablesaw-priority="persist">Diagnosis*</th>
|
||
<th>A1C Level</th>
|
||
</tr>
|
||
</thead>
|
||
<tbody>
|
||
<tr>
|
||
<td class="tablesaw-cell-persist">Normal</td>
|
||
<td>below 5.7 percent</td>
|
||
</tr>
|
||
<tr>
|
||
<td class="tablesaw-cell-persist">Prediabetes</td>
|
||
<td>5.7 to 6.4 percent</td>
|
||
</tr>
|
||
<tr>
|
||
<td class="tablesaw-cell-persist">Diabetes</td>
|
||
<td>6.5 percent or above</td>
|
||
</tr>
|
||
</tbody>
|
||
</table>
|
||
<p>When using the A1C test for diagnosis, your doctor will send your blood sample taken from a vein to a lab that uses an NGSP-certified method. <a href="https://ngsp.org/">The NGSP</a>, formerly called the National Glycohemoglobin Standardization Program, certifies that makers of A1C tests provide results that are consistent and comparable with those used in the <a href="/about-niddk/research-areas/diabetes/blood-glucose-control-studies-type-1-diabetes-dcct-edic">Diabetes Control and Complications Trial</a>.</p>
|
||
<p>Blood samples analyzed in a doctor’s office or clinic, known as point-of-care tests, should not be used for diagnosis.</p>
|
||
<p>The A1C test should not be used to diagnose <a href="/health-information/diabetes/overview/what-is-diabetes/type-1-diabetes">type 1 diabetes</a>, <a class="dictionary-term" href="/Dictionary/G/gestational-diabetes">gestational diabetes</a>, or <a href="https://medlineplus.gov/cysticfibrosis.html">cystic fibrosis</a>-related diabetes. The A1C test may give <a href="/health-information/diagnostic-tests/a1c-test#affected">false results in people with certain conditions</a>.</p>
|
||
<p>Having prediabetes is a risk factor for developing type 2 diabetes. Within the prediabetes A1C range of 5.7 to 6.4 percent, the higher the A1C, the greater the risk of diabetes.</p>
|
||
<h2 id="pregnancy">Is the A1C test used during pregnancy?</h2>
|
||
<p>Health care professionals may use the A1C test early in pregnancy to see if a woman with risk factors had undiagnosed diabetes before becoming pregnant. Since the A1C test reflects your average blood glucose levels over the past 3 months, testing early in pregnancy may include values reflecting time before you were pregnant. The <a href="/health-information/diabetes/overview/tests-diagnosis#glucosechallenge">glucose challenge test</a> or the <a class="dictionary-term" href="/Dictionary/O/oral-glucose-tolerance-test">oral glucose tolerance test </a>(OGTT) are used to check for <a href="/health-information/diabetes/overview/what-is-diabetes/gestational">gestational diabetes</a>, usually between 24 and 28 weeks of pregnancy. If you had gestational diabetes, you should be tested for diabetes no later than 12 weeks after your baby is born. If your blood glucose is still high, you may have type 2 diabetes. Even if your blood glucose is normal, you still have a greater chance of developing type 2 diabetes in the future and should get tested every 3 years.</p>
|
||
<h2 id="other">Can other blood glucose tests be used to diagnose type 2 diabetes and prediabetes?</h2>
|
||
<p>Yes. Health care professionals also use the <a class="dictionary-term" href="/Dictionary/F/fasting-blood-glucose-test">fasting plasma glucose (FPG) test</a> and the OGTT to diagnose type 2 diabetes and prediabetes. For these <a href="/health-information/diabetes/overview/tests-diagnosis">blood glucose tests used to diagnose diabetes</a>, you must fast at least 8 hours before you have your blood drawn. If you have symptoms of diabetes, your doctor may use the <a class="dictionary-term" href="/Dictionary/R/random-plasma-glucose-test">random plasma glucose test</a>, which doesn’t require fasting. In some cases, health care professionals use the A1C test to help confirm the results of another blood glucose test.</p>
|
||
<h2 id="different">Can the A1C test result in a different diagnosis than the blood glucose tests?</h2>
|
||
<p>Yes. In some people, a blood glucose test may show diabetes when an A1C test does not. The reverse can also occur—an A1C test may indicate diabetes even though a blood glucose test does not. Because of these differences in test results, health care professionals repeat tests before making a diagnosis.</p>
|
||
<p>People with differing test results may be in an early stage of the disease, when blood glucose levels have not risen high enough to show up on every test. In this case, health care professionals may choose to follow the person closely and repeat the test in several months.</p>
|
||
<h2 id="vary">Why do diabetes blood test results vary?</h2>
|
||
<p>Lab test results can vary from day to day and from test to test. This can be a result of the following factors:</p>
|
||
<h3>Blood glucose levels move up and down</h3>
|
||
<p>Your results can vary because of natural changes in your blood glucose level. For example, your blood glucose level moves up and down when you eat or exercise. Sickness and stress also can affect your blood glucose test results. A1C tests are less likely to be affected by short-term changes than FPG or OGTT tests.</p>
|
||
<p>The following chart shows how multiple blood glucose measurements over 4 days compare with an A1C measurement.</p>
|
||
<h4>Blood Glucose Measurements Compared with A1C Measurements over 4 Days</h4>
|
||
<figure class="large center">
|
||
<a class="expand" target="_blank" href="/-/media/Images/Health-Information/Diabetes/A1C-lineChart_850x416.png" title="View full-sized image"></a>
|
||
<img alt="Graph shows blood glucose in mg/dL on the y-axis and day of the week on the x-axis. A black line straight across the center shows an A1C of 7.0%. A blue line starts at 145 mg/dL and rises and falls, with the lowest level at 140 mg/dL and the highest at 175 mg/dL pre-lunch on Monday. Each day, the fasting or pre-breakfast level is the lowest level." src="/-/media/Images/Health-Information/Diabetes/A1C-lineChart_850x416.png" />
|
||
<figcaption>Blood glucose (mg/dL) measurements were taken four times per day (fasting or pre-breakfast, pre-lunch, pre-dinner, and bedtime).</figcaption>
|
||
</figure>
|
||
<p>The straight black line shows an A1C measurement of 7.0 percent. The blue line shows an example of how blood glucose test results might look from self-monitoring four times a day over a 4-day period.</p>
|
||
<h3 id="affected">A1C tests can be affected by changes in red blood cells or hemoglobin</h3>
|
||
<p>Conditions that change the life span of red blood cells, such as recent blood loss, <a href="https://www.nhlbi.nih.gov/health-topics/sickle-cell-disease">sickle cell disease</a>, <a class="dictionary-term" href="/Dictionary/E/erythropoietin">erythropoietin</a> treatment, <a class="dictionary-term" href="/Dictionary/H/hemodialysis">hemodialysis</a>, or transfusion, can change A1C levels.</p>
|
||
<p>A falsely high A1C result can occur in people who are very low in iron; for example, those with <a href="https://www.nhlbi.nih.gov/health-topics/iron-deficiency-anemia">iron-deficiency anemia</a>. Other causes of false A1C results include <a href="/health-information/kidney-disease/kidney-failure">kidney failure</a> or <a href="/health-information/liver-disease">liver disease</a>.</p>
|
||
<p>If you’re of African, Mediterranean, or Southeast Asian descent or have family members with sickle cell anemia or a <a href="https://www.nhlbi.nih.gov/health-topics/thalassemias">thalassemia</a>, an A1C test can be unreliable for diagnosing or monitoring diabetes and prediabetes. People in these groups may have a different type of hemoglobin, known as a hemoglobin variant, which can interfere with some A1C tests. Most people with a hemoglobin variant have no symptoms and may not know that they carry this type of hemoglobin. Health care professionals may suspect interference—a falsely high or low result—when your A1C and blood glucose test results don’t match.</p>
|
||
<figure class="small center">
|
||
<img alt="Doctor sharing test results with patient." src="/-/media/Images/Health-Information/Digestive-Diseases/Hem_man_doctor.jpg" />
|
||
<figcaption>If you’re of African, Mediterranean, or Southeast Asian descent, you could have a different type of hemoglobin that affects your diabetes care.</figcaption>
|
||
</figure>
|
||
<p>Not all A1C tests are unreliable for people with a hemoglobin variant. People with false results from one type of A1C test may need a different type of A1C test to measure their average blood glucose level. The NGSP provides information for health care professionals about <a href="https://ngsp.org/interf.asp">which A1C tests are appropriate to use for specific hemoglobin variants</a>.</p>
|
||
<p>Read about <a href="/health-information/diagnostic-tests/a1c-test-race-ethnicity">diabetes blood tests for people of African, Mediterranean, or Southeast Asian descent</a>. The NIDDK has information for health care providers on <a href="/health-information/professionals/clinical-tools-patient-management/diabetes/sickle-cell-trait-hemoglobinopathies-diabetes">Sickle Cell Trait & Other Hemoglobinopathies & Diabetes</a>.</p>
|
||
<h3>Small changes in temperature, equipment, or sample handling</h3>
|
||
<p>Even when the same blood sample is repeatedly measured in the same lab, the results may vary because of small changes in temperature, equipment, or sample handling. These factors tend to affect glucose measurements—fasting and OGTT—more than the A1C test.</p>
|
||
<figure class="small center">
|
||
<img alt="Health care professional shares test results with woman." src="/-/media/Images/Health-Information/Urologic/DoctorWithPatient_335x224.jpg" />
|
||
<figcaption>Your health care professional can help you understand your test results.</figcaption>
|
||
</figure>
|
||
<p>Health care professionals understand these variations and repeat lab tests for confirmation. Diabetes develops over time, so even with variations in test results, health care professionals can tell when overall blood glucose levels are becoming too high.</p>
|
||
<h2 id="precise">How precise is the A1C test?</h2>
|
||
<p>When repeated, the A1C test result can be slightly higher or lower than the first measurement. This means, for example, an A1C reported as 6.8 percent on one test could be reported in a range from 6.4 to 7.2 percent on a repeat test from the same blood sample.<sup>3</sup> In the past, this range was larger but new, stricter quality-control standards mean more precise A1C test results.</p>
|
||
<p>Health care professionals can visit <a href="https://ngsp.org/">ngsp.org</a> to find information about the precision of the A1C test used by their lab.</p>
|
||
<h2 id="after">How is the A1C test used after diagnosis of diabetes?</h2>
|
||
<p>Your health care professional may use the A1C test to set your treatment goals, modify therapy, and monitor your diabetes management.</p>
|
||
<p>Experts recommend that people with diabetes have an A1C test at least twice a year.<sup>4</sup> Health care professionals may check your A1C more often if you aren’t meeting your treatment goals.<sup>4</sup></p>
|
||
<h2 id="goal">What A1C goal should I have?</h2>
|
||
<p>People will have different A1C targets, depending on their diabetes history and their general health. You should discuss your A1C target with your health care professional. Studies have shown that some people with diabetes can reduce the risk of <a href="/health-information/diabetes/overview/preventing-problems">diabetes complications</a> by keeping A1C levels below 7 percent.</p>
|
||
<p>Managing blood glucose early in the course of diabetes may provide benefits for many years to come. However, an A1C level that is safe for one person may not be safe for another. For example, keeping an A1C level below 7 percent may not be safe if it leads to problems with <a href="/health-information/diabetes/overview/preventing-problems/low-blood-glucose-hypoglycemia">hypoglycemia</a>, also called low blood glucose.</p>
|
||
<p>Less strict blood glucose control, or an A1C between 7 and 8 percent—or even higher in some circumstances—may be appropriate in people who have</p>
|
||
<ul>
|
||
<li>limited life expectancy</li>
|
||
<li>long-standing diabetes and trouble reaching a lower goal</li>
|
||
<li>severe hypoglycemia or inability to sense hypoglycemia (also called hypoglycemia unawareness)</li>
|
||
<li>advanced diabetes complications such as <a href="/health-information/kidney-disease/chronic-kidney-disease-ckd">chronic kidney disease</a>, nerve problems, or cardiovascular disease</li>
|
||
</ul>
|
||
<h2 id="glucose">How does A1C relate to estimated average glucose?</h2>
|
||
<p><a href="https://ngsp.org/A1ceAG.asp">Estimated average glucose (eAG) is calculated from your A1C</a>. Some laboratories report eAG with A1C test results. The eAG number helps you relate your A1C to daily glucose monitoring levels. The eAG calculation converts the A1C percentage to the same units used by home glucose meters—milligrams per deciliter (mg/dL).</p>
|
||
<p>The eAG number will not match daily glucose readings because it’s a long-term average—rather than your blood glucose level at a single time, as is measured with a home glucose meter.</p>
|
||
<h2 id="changes">Will the A1C test show short-term changes in blood glucose levels?</h2>
|
||
<p>Large changes in your blood glucose levels over the past month will show up in your A1C test result, but the A1C test doesn’t show sudden, temporary increases or decreases in blood glucose levels. Even though A1C results represent a long-term average, blood glucose levels within the past 30 days have a greater effect on the A1C reading than those in previous months.</p>
|
||
<h2 id="clinicaltrials">Clinical Trials for the A1C Test and Diabetes</h2>
|
||
<p>The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and other components of the National Institutes of Health (NIH) conduct and support research into many diseases and conditions.</p>
|
||
<h3>What are clinical trials and are they right for you?</h3>
|
||
<p>Clinical trials are part of clinical research and at the heart of all medical advances. Clinical trials look at new ways to prevent, detect, or treat disease. Scientists are conducting research to learn more about diabetes, including studies about A1C. For example</p>
|
||
<ul>
|
||
<li>how the relationship between A1C and blood glucose may vary in different racial and ethnic groups</li>
|
||
<li>to find other tests that may be better than A1C for some people</li>
|
||
<li>to look for ways to further improve A1C test results. Because the A1C value depends on the average life span of your red blood cells, knowing whether the life span of your red blood cells is longer or shorter may give your doctor helpful information.</li>
|
||
</ul>
|
||
<p>Researchers also use clinical trials to look at other aspects of care, such as improving the quality of life for people with chronic illnesses. <a href="https://www.nih.gov/health-information/nih-clinical-research-trials-you">Find out if clinical trials are right for you</a>.</p>
|
||
<h3>What clinical trials are open?</h3>
|
||
<p>Clinical trials that are currently open and are recruiting can be viewed at <span style="white-space: nowrap;"><a href="https://clinicaltrials.gov/">ClinicalTrials.gov</a>.</span></p>
|
||
<h2>References</h2>
|
||
<aside class="references">
|
||
<p>[1] Gillett MJ. International Expert Committee report on the role of the A1C assay in the diagnosis of diabetes. <em>Diabetes Care</em>. 2009;32(7):1327–1334. </p>
|
||
<p>[2] American Diabetes Association. 2. Classification and diagnosis of diabetes: Standards of Medical Care in Diabetes—2018. <em>Diabetes Care</em>. 2018;41(suppl 1):S13–S27.</p>
|
||
<p>[3] Penttilä I, Penttilä K, Holm P, et al. Methods, units and quality requirements for the analysis of haemoglobin A1c in diabetes mellitus. <em>World Journal of Methodology</em>. 2016;6(2):133–142.</p>
|
||
<p>[4] American Diabetes Association. 6. Glycemic targets: Standards of Medical Care in Diabetes—2018. <em>Diabetes Care</em>. 2018;41(suppl 1):S55–S64.</p>
|
||
</aside>
|
||
</div> <div class="dk-review-date">Last Reviewed April 2018</div>
|
||
<div id="13d00f781f1942eab0544cd02fa07678" class="dk-share">
|
||
|
||
|
||
<span>Share<span class="sr-only"> this page</span></span>
|
||
<div class="dk-share-buttons" data-lang="en">
|
||
|
||
<button type="button" class="shr-print" title="Print this page" onclick="window.print();return false;">Print</button>
|
||
<a class="shr-facebook no-disclaimer" title="Share this page on Facebook" href="#share-13d00f781f1942eab0544cd02fa07678" target="_blank" rel="nofollow noopener">Facebook</a>
|
||
<a class="shr-x no-disclaimer" title="Post this page on X" href="#share-13d00f781f1942eab0544cd02fa07678" target="_blank" rel="nofollow noopener">X</a>
|
||
<a class="shr-email" title="Email this page" href="#share-13d00f781f1942eab0544cd02fa07678" target="_self" rel="nofollow noopener">Email</a>
|
||
|
||
<button type="button" class="shr-more" title="More sharing options" aria-expanded="false">More Options</button>
|
||
|
||
<a class="shr-whatsapp no-disclaimer" title="Share this page via WhatsApp" href="#share-13d00f781f1942eab0544cd02fa07678" target="_self" rel="nofollow noopener">WhatsApp</a>
|
||
<a class="shr-linkedin no-disclaimer" title="Share this page on LinkedIn" href="#share-13d00f781f1942eab0544cd02fa07678" target="_blank" rel="nofollow noopener">LinkedIn</a>
|
||
<a class="shr-reddit no-disclaimer" title="Share this page on Reddit" href="#share-13d00f781f1942eab0544cd02fa07678" target="_blank" rel="nofollow noopener">Reddit</a>
|
||
<a class="shr-pinterest no-disclaimer" title="Share this page on Pinterest" href="#share-13d00f781f1942eab0544cd02fa07678" target="_blank" rel="nofollow noopener">Pinterest</a>
|
||
|
||
<button type="button" class="shr-copy" title="Copy a link for sharing to the clipboard">Copy Link</button>
|
||
</div>
|
||
<script src="/_ux/niddk/9.37.0/scripts/modules/social-share.js" type="module"></script>
|
||
|
||
</div>
|
||
|
||
<div class="disclaimer">
|
||
<p>
|
||
This content is provided as a service of the <a href="https://www.niddk.nih.gov/">National Institute of Diabetes and Digestive and Kidney Diseases</a>
|
||
(NIDDK), part of the National Institutes of Health. NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by NIDDK is carefully reviewed by NIDDK scientists and other experts.<br />
|
||
|
||
</p>
|
||
<p>
|
||
|
||
</p>
|
||
<p>
|
||
|
||
</p>
|
||
</div>
|
||
</article>
|
||
</div>
|
||
</div>
|
||
</main>
|
||
<footer id="main-footer" itemscope itemtype="http://schema.org/GovernmentOrganization" itemid="https://www.niddk.nih.gov">
|
||
<meta itemprop="name" content="National Institute of Diabetes and Digestive and Kidney Diseases">
|
||
<meta itemprop="alternateName" content="NIDDK">
|
||
<link itemprop="url" href="https://www.niddk.nih.gov">
|
||
<link itemprop="logo" href="/images/site-logo.png">
|
||
<link itemprop="sameAs" href="https://en.wikipedia.org/wiki/National_Institute_of_Diabetes_and_Digestive_and_Kidney_Diseases">
|
||
<span itemprop="address" itemscope itemtype="http://schema.org/PostalAddress">
|
||
<meta itemprop="name" content="NIDDK, NIH">
|
||
<meta itemprop="streetAddress" content="31 Center Drive, MSC 2560">
|
||
<meta itemprop="addressLocality" content="Bethesda">
|
||
<meta itemprop="addressRegion" content="MD">
|
||
<meta itemprop="addressCountry" content="US">
|
||
<meta itemprop="postalCode" content="20892-2560">
|
||
</span>
|
||
<section id="contact">
|
||
<div class="grid">
|
||
<h2>Contact Us</h2>
|
||
<div class="contact-flex v2">
|
||
<address itemprop="department" itemscope="" itemtype="http://schema.org/GovernmentOffice">
|
||
<meta itemprop="name" content="The National Institute of Diabetes and Digestive and Kidney Diseases Health Information Center" />
|
||
<link itemprop="url" href="/health-information" />
|
||
<link itemprop="image" href="/images/site-logo.png" />
|
||
<meta itemprop="telephone" content="+1-800-860-8747" />
|
||
<meta itemprop="openingHours" content="Mo-Fr 08:30-17:00" />
|
||
<meta itemprop="address" content="9000 Rockville Pike, Bethesda, MD 20892, United States" />
|
||
<div class="contact-time">
|
||
<i class="i-clock-o"></i>
|
||
<span>
|
||
<strong>Hours:</strong>
|
||
<time datetime="08:30">8:30 a.m.</time>
|
||
to
|
||
<time datetime="17:00">5 p.m.</time>
|
||
ET, Monday - Friday</span>
|
||
</div>
|
||
<a class="contact-email" href="mailto:healthinfo@niddk.nih.gov">
|
||
<i class="i-envelope-o"></i>
|
||
<span>
|
||
<strong>Email:</strong>
|
||
<span class="lnk" itemprop="email">healthinfo@niddk.nih.gov</span></span>
|
||
</a>
|
||
<a class="contact-mobile" href="tel:1-800-860-8747" itemprop="contactPoint" itemscope="" itemtype="http://schema.org/ContactPoint">
|
||
<i class="i-mobile"></i>
|
||
<span>
|
||
<strong>Phone:</strong>
|
||
<span class="lnk" itemprop="telephone"><span class="hide">+</span>1-800-860-8747</span>
|
||
<meta itemprop="contactType" content="customer service" />
|
||
<meta itemprop="contactOption" content="TollFree" />
|
||
</span>
|
||
</a>
|
||
<a class="contact-tty" href="tel:711" itemprop="contactPoint" itemscope="" itemtype="http://schema.org/ContactPoint">
|
||
<i class="i-tty"></i>
|
||
<span>
|
||
<strong>TTY:</strong>
|
||
<span class="lnk" itemprop="telephone"><span class="hide">+</span>711</span>
|
||
<meta itemprop="contactType" content="customer service" />
|
||
<meta itemprop="contactOption" content="HearingImpairedSupported" />
|
||
<meta itemprop="contactOption" content="TollFree" />
|
||
</span>
|
||
</a>
|
||
<div class="print-social">
|
||
<svg viewbox="0 0 600 100" fill="currentcolor">
|
||
<path d="M550,9.01c13.35,0,14.93.05,20.2.29,4.87.22,7.52,1.04,9.28,1.72,2.33.91,4,1.99,5.75,3.74,1.75,1.75,2.83,3.42,3.74,5.75.68,1.76,1.5,4.41,1.72,9.28.24,5.27.29,6.85.29,20.2s-.05,14.93-.29,20.2c-.22,4.87-1.04,7.52-1.72,9.28-.91,2.33-1.99,4-3.74,5.75-1.75,1.75-3.42,2.83-5.75,3.74-1.76.68-4.41,1.5-9.28,1.72-5.27.24-6.85.29-20.2.29s-14.93-.05-20.2-.29c-4.87-.22-7.52-1.04-9.28-1.72-2.33-.91-4-1.99-5.75-3.74-1.75-1.75-2.83-3.42-3.74-5.75-.68-1.76-1.5-4.41-1.72-9.28-.24-5.27-.29-6.85-.29-20.2s.05-14.93.29-20.2c.22-4.87,1.04-7.52,1.72-9.28.91-2.33,1.99-4,3.74-5.75,1.75-1.75,3.42-2.83,5.75-3.74,1.76-.68,4.41-1.5,9.28-1.72,5.27-.24,6.85-.29,20.2-.29h0ZM550,0c-13.58,0-15.28.06-20.62.3-5.32.24-8.96,1.09-12.14,2.32-3.29,1.28-6.08,2.99-8.86,5.77-2.78,2.78-4.49,5.57-5.77,8.85-1.24,3.18-2.08,6.82-2.32,12.14-.24,5.33-.3,7.04-.3,20.62s.06,15.28.3,20.62c.24,5.32,1.09,8.96,2.32,12.14,1.28,3.29,2.99,6.08,5.77,8.86,2.78,2.78,5.57,4.49,8.86,5.77,3.18,1.24,6.82,2.08,12.14,2.32,5.33.24,7.04.3,20.62.3s15.28-.06,20.62-.3c5.32-.24,8.96-1.09,12.14-2.32,3.29-1.28,6.08-2.99,8.86-5.77,2.78-2.78,4.49-5.57,5.77-8.86,1.24-3.18,2.08-6.82,2.32-12.14.24-5.33.3-7.04.3-20.62s-.06-15.28-.3-20.62c-.24-5.32-1.09-8.96-2.32-12.14-1.28-3.29-2.99-6.08-5.77-8.86-2.78-2.78-5.57-4.49-8.86-5.77-3.18-1.24-6.82-2.08-12.14-2.32C565.28.06,563.58,0,550,0h0ZM550,24.32c-14.18,0-25.67,11.5-25.67,25.67s11.49,25.67,25.67,25.67,25.67-11.49,25.67-25.67-11.49-25.67-25.67-25.67ZM550,66.66c-9.21,0-16.67-7.46-16.67-16.67s7.46-16.67,16.67-16.67,16.67,7.46,16.67,16.67-7.46,16.67-16.67,16.67ZM582.69,23.31c0,3.31-2.69,6-6,6s-6-2.69-6-6,2.69-6,6-6,6,2.69,6,6Z"></path>
|
||
<path d="M485.16,15.65c-1.61-6.13-6.45-10.97-12.58-12.66-11.05-2.98-55.4-2.98-55.4-2.98,0,0-44.35,0-55.48,2.98-6.13,1.61-10.89,6.45-12.58,12.66-2.9,11.13-2.9,34.36-2.9,34.36,0,0,0,23.23,2.98,34.35,1.61,6.13,6.45,10.97,12.58,12.66,11.05,2.98,55.4,2.98,55.4,2.98,0,0,44.35,0,55.48-2.98,6.13-1.61,10.89-6.45,12.58-12.66,2.9-11.13,2.9-34.35,2.9-34.35,0,0,0-23.23-2.98-34.35ZM402.66,71.13V28.87l37.1,21.13-37.1,21.13h0Z"></path>
|
||
<path d="M334.34,3v94c0,1.66-1.34,3-3,3h-27.99v-38.74h12.96l1.95-15.1h-14.91v-9.64c0-4.36,1.17-7.29,7.49-7.29l7.94-.07v-13.48c-1.37-.2-6.12-.59-11.59-.59-11.52,0-19.47,7.03-19.47,19.92v11.13h-13.02v15.1h13.02v38.74h-50.39c-1.66,0-3-1.34-3-3V3c0-1.66,1.34-3,3-3h94c1.66,0,3,1.34,3,3Z"></path>
|
||
<path d="M198.99,0h16.96l-37.07,42.36,43.61,57.64h-34.15l-26.73-34.97-30.6,34.97h-16.96l39.63-45.31L111.86,0h35l24.18,31.96L198.99,0ZM193.02,89.86h9.4L141.75,9.63h-10.09l61.36,80.23Z"></path>
|
||
<path d="M15.43,83.72h15.04v-45.18h-15.04v45.18ZM31.45,24.61c-.07-4.43-3.26-7.81-8.4-7.81s-8.53,3.39-8.53,7.81,3.26,7.81,8.33,7.81h.07c5.27,0,8.53-3.52,8.53-7.81h0ZM69.53,83.72h15.04v-25.91c0-13.87-7.42-20.31-17.32-20.31-8.07,0-11.65,4.49-13.61,7.62h.13v-6.58h-15.04s.2,4.23,0,45.18h15.04v-25.26c0-1.3.07-2.67.46-3.65,1.11-2.67,3.58-5.47,7.75-5.47,5.4,0,7.55,4.1,7.55,10.22v24.15h0ZM100,18.75v62.5c0,10.35-8.4,18.75-18.75,18.75H18.75c-10.35,0-18.75-8.4-18.75-18.75V18.75C0,8.4,8.4,0,18.75,0h62.5c10.35,0,18.75,8.4,18.75,18.75Z"></path>
|
||
</svg>
|
||
<span>@NIDDKgov</span>
|
||
</div>
|
||
</address>
|
||
<div class="live-chat">
|
||
<h3>Chat</h3>
|
||
<div class="footer-live-chat">
|
||
<niddk-chatbadge lang="en"></niddk-chatbadge>
|
||
<div>
|
||
Live Chat Available<br />
|
||
8:30 a.m. - 5 p.m. ET<br />
|
||
Monday - Friday
|
||
</div>
|
||
</div>
|
||
</div>
|
||
<div class="follow-us">
|
||
<h3>
|
||
<a href="/news/follow-us">Follow Us</a>
|
||
</h3>
|
||
<a href="https://www.linkedin.com/company/national-institute-of-diabetes-and-digestive-and-kidney-diseases-niddk" class="linkedin" title="Follow NIDDK on LinkedIn" itemprop="sameAs" target="_blank" rel="noopener noreferrer">LinkedIn</a>
|
||
<a href="https://x.com/NIDDKgov" class="x-social" title="Follow NIDDK on X" itemprop="sameAs" target="_blank" rel="noopener noreferrer">X</a>
|
||
<a href="https://www.facebook.com/NIDDKgov" class="facebook" title="Like NIDDK on Facebook" itemprop="sameAs" target="_blank" rel="noopener noreferrer">Facebook</a>
|
||
<a href="https://www.youtube.com/user/NIDDKgov" class="youtube" title="Subscribe to NIDDK on YouTube" target="_blank" rel="noopener noreferrer">YouTube</a>
|
||
<a href="https://www.instagram.com/niddkgov" class="instagram" title="Follow NIDDK on Instagram" target="_blank" rel="noopener noreferrer">Instagram</a>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</section><p class="grid tagline">NIH… Turning Discovery Into Health ®</p>
|
||
|
||
<div class="sub-footer">
|
||
<div class="grid">
|
||
<div role="region" aria-label="Policy links">
|
||
<ul class="horizontal-links">
|
||
<li><a href="/privacy-policy">Privacy Policy</a></li>
|
||
<li><a href="/freedom-information-act">Freedom of Information Act</a></li>
|
||
<li><a href="/accessibility">Accessibility</a></li>
|
||
<li><a href="/disclaimers">Disclaimers</a></li>
|
||
<li><a href="/copyright">Copyright</a></li>
|
||
<li><a href="https://www.hhs.gov/vulnerability-disclosure-policy/index.html">Vulnerability Disclosure Policy</a></li>
|
||
</ul>
|
||
</div>
|
||
<div role="region" aria-label="Utility links">
|
||
<ul class="horizontal-links">
|
||
<li><a href="/site-map">Site Map</a></li>
|
||
<li><a href="https://intranet.niddk.nih.gov/SitePages/Home.aspx" rel="nofollow">For Staff Only</a></li>
|
||
<li><a href="https://public.govdelivery.com/accounts/USNIDDK/subscriber/new">Get Email Updates</a></li>
|
||
</ul>
|
||
</div>
|
||
<div role="region" aria-label="Related government sites">
|
||
<ul class="horizontal-links">
|
||
<li>
|
||
<a href="https://www.hhs.gov/">
|
||
<span>U.S. Department of Health and Human Services</span>
|
||
</a>
|
||
</li>
|
||
<li itemprop="memberOf" itemscope="" itemtype="http://schema.org/GovernmentOrganization">
|
||
<a href="https://www.nih.gov/" itemprop="url">
|
||
<span itemprop="name">National Institutes of Health</span>
|
||
</a>
|
||
<meta itemprop="alternateName" content="NIH" />
|
||
</li>
|
||
</ul>
|
||
</div>
|
||
<niddk-chatcontrol href-on="/System/start-chat" src-en="/chatbeacon/NIDDK/1/scripts/chatbeacon.js?accountId=1&siteId=1&queueId=1&m=0&i=1&b=1&c=1&theme=frame" src-es="/chatbeacon/NIDDK/1/scripts/chatbeacon.js?accountId=1&siteId=1&queueId=4&m=0&i=1&b=1&c=1&theme=frame" statuslinkid="_lcstatuslink"></niddk-chatcontrol>
|
||
</div>
|
||
</div>
|
||
<iframe src="https://www.niddk.nih.gov/health-information/diagnostic-tests/a1c-test?tracking=true" style="height:0;width:0;visibility:hidden;display:none;" aria-hidden="true"></iframe>
|
||
|
||
<iframe style="height:0;width:0;visibility:hidden;display:none;" src="about:blank" aria-hidden="true"></iframe>
|
||
</footer>
|
||
<div class="page-mask"></div>
|
||
</div>
|
||
|
||
<script src="/_ux/niddk/9.37.0/deps/jquery.min.js" defer></script>
|
||
<script src="/_ux/niddk/9.37.0/deps/slick-carousel/slick.min.js" defer></script>
|
||
<script src="/_ux/niddk/9.37.0/deps/jquery-scrolltabs/jquery.scrolltabs.min.js" defer></script>
|
||
<script src="/_ux/niddk/9.37.0/deps/magnific-popup/jquery.magnific-popup.min.js" defer></script>
|
||
<script src="/_ux/niddk/9.37.0/deps/tablesaw/tablesaw.jquery.min.js" defer></script>
|
||
|
||
<script src="/_ux/niddk/9.37.0/scripts/niddk-main.js" defer></script>
|
||
<script src="/_ux/niddk/9.37.0/scripts/modules/live-chat.js" type="module"></script>
|
||
|
||
|
||
|
||
<meta itemprop="image" content="https://www.niddk.nih.gov/-/media/Images/Components/Default-Social-Media-Images/Health-Information-Card-ALT3.png" />
|
||
<meta itemprop="lastReviewed" content="2018-04-20T19:09:00.0000000Z-05:00" />
|
||
<span itemprop="inLanguage" itemscope itemtype="http://schema.org/Language">
|
||
<meta itemprop="name" content="English" />
|
||
<meta itemprop="alternateName" content="en-US" />
|
||
</span>
|
||
|
||
</body>
|
||
</html> |