publicdata/nih-gov
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
nih-gov/medlineplus.gov/lab-tests/hemoglobin-a1c-hba1c-test/index.html
Scott Williams 7bcb500d37 Initial commit.
2025-02-26 13:17:41 -05:00

661 lines
40 KiB
HTML
Raw Permalink Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!DOCTYPE html>
<html lang="en" id="lab_test" class="nojs us" data-root="https://medlineplus.gov/">
<head>
<meta charset="utf-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1" />
<meta http-equiv="window-target" content="_top" />
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<link rel="canonical" href="https://medlineplus.gov/lab-tests/hemoglobin-a1c-hba1c-test/" />
<link rel="alternate" hreflang="en" href="https://medlineplus.gov/lab-tests/hemoglobin-a1c-hba1c-test/" />
<link rel="alternate" hreflang="es" href="https://medlineplus.gov/spanish/pruebas-de-laboratorio/prueba-de-hemoglobina-a1c/" />
<meta name="ac-dictionary" content="medlineplus-ac-dictionary" />
<meta name="description" content="A hemoglobin A1C test is a blood test that measures the amount of glucose (sugar) attached to hemoglobin. High A1C levels can be a sign of diabetes. Learn more." />
<link rel="shortcut icon" href="https://medlineplus.gov/images/favicon.ico" type="image/x-icon" />
<link rel="apple-touch-icon" href="https://medlineplus.gov/images/touch-icon.png" />
<meta property="fb:app_id" content="1042245625821448" />
<meta property="og:title" content="Hemoglobin A1C (HbA1c) Test: MedlinePlus Medical Test" />
<meta property="og:url" content="https://medlineplus.gov/lab-tests/hemoglobin-a1c-hba1c-test/" />
<meta property="og:image" content="https://medlineplus.gov/images/LabTests_Share.jpg" />
<meta property="og:image" content="https://medlineplus.gov/images/LabTest_Share2.jpg" />
<meta property="og:image" content="https://medlineplus.gov/images/LabTests_Share3.jpg" />
<meta property="og:description" content="A hemoglobin A1C test is a blood test that measures the amount of glucose (sugar) attached to hemoglobin. High A1C levels can be a sign of diabetes. Learn more." />
<meta name="twitter:card" content="summary_large_image" />
<meta name="twitter:site" content="@medlineplus" />
<meta name="twitter:creator" content="@medlineplus" />
<meta name="twitter:title" content="Hemoglobin A1C (HbA1c) Test: MedlinePlus Medical Test" />
<meta name="twitter:description" content="A hemoglobin A1C test is a blood test that measures the amount of glucose (sugar) attached to hemoglobin. High A1C levels can be a sign of diabetes. Learn more." />
<meta name="twitter:image" content="https://medlineplus.gov/images/LabTests_Share.jpg" />
<meta name="twitter:image:alt" content=""/>
<meta property="og:image:alt" content="" />
<title>Hemoglobin A1C (HbA1c) Test: MedlinePlus Medical Test</title>
<link rel="stylesheet" href="https://medlineplus.gov/css/common_new.css?1738957220916" />
<!--[if IE 8]> <link rel="stylesheet" href="https://medlineplus.gov/css/ie8/common.css"> <![endif]-->
<link rel="stylesheet" href="https://medlineplus.gov/uswds/css/uswds_styles.css" />
<script type="text/javascript">document.getElementsByTagName('html')[0].className = document.getElementsByTagName('html')[0].className.replace( /(?:^|\s)nojs(?!\S)/g , '').trim();</script>
<script src="https://medlineplus.gov/uswds/js/uswds-init.min.js" type="text/javascript"></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-MMVM77');</script>
</head>
<body>
<noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-MMVM77"
height="0" width="0" style="display:none;visibility:hidden" title="googletagmanager"></iframe></noscript>
<a name="top" id="top"></a>
<a class="hide-offscreen" href="#start">Skip navigation</a>
<section
class="usa-banner"
aria-label="Official website of the United States government"
>
<div class="usa-accordion">
<header class="usa-banner__header">
<div class="usa-banner__inner">
<div class="grid-col-auto">
<img
aria-hidden="true"
class="usa-banner__header-flag"
src="https://medlineplus.gov/uswds/img/us_flag_small.png"
alt=""
/>
</div>
<div class="grid-col-fill tablet:grid-col-auto" aria-hidden="true">
<p class="usa-banner__header-text">
An official website of the United States government
</p>
<p class="usa-banner__header-action">Here’s how you know</p>
</div>
<button
type="button"
class="usa-accordion__button usa-banner__button"
aria-expanded="false"
aria-controls="gov-banner-default-default"
>
<span class="usa-banner__button-text">Here’s how you know</span>
</button>
</div>
</header>
<div
class="usa-banner__content usa-accordion__content"
id="gov-banner-default-default"
>
<div class="grid-row grid-gap-lg">
<div class="usa-banner__guidance tablet:grid-col-6">
<img
class="usa-banner__icon usa-media-block__img"
src="https://medlineplus.gov/uswds/img/icon-dot-gov.svg"
role="img"
alt=""
aria-hidden="true"
/>
<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 tablet:grid-col-6">
<img
class="usa-banner__icon usa-media-block__img"
src="https://medlineplus.gov/uswds/img/icon-https.svg"
role="img"
alt=""
aria-hidden="true"
/>
<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-description-default"
focusable="false"
>
<title id="banner-lock-title-default">Lock</title>
<desc id="banner-lock-description-default">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>
</div>
</section>
<div id="mplus-wrap">
<header>
<div id="mplus-header">
<div id="mplus-orgs">
<a href="https://www.nih.gov/" class="nih-org" target="_blank" title="National Institutes of Health">
<img class="nihlogo" src="https://medlineplus.gov/images/nihlogo.png" alt="National Institutes of Health"/>
</a><a href="https://www.nlm.nih.gov/" target="_blank"> National Library of Medicine</a>
</div>
<div id="mplus-logo" class="years-25">
<a href="https://medlineplus.gov/">
<img alt="MedlinePlus Trusted Health Information for You" title="MedlinePlus Trusted Health Information for You" src="https://medlineplus.gov/images/m_logo_25.png"/>
</a>
</div>
<div id="mplus-nav">
<div aria-live="polite" class="sm-live-area hide-offscreen"></div>
<button id="sm-menu-btn" class="navmenu-btn" title="Menu" role="button" aria-controls="mplus-menu-list" type="submit">Menu<span class="icon icon-nav-menu"></span></button>
<ul id="mplus-menu-list" class="nav-list">
<li><a href="https://medlineplus.gov/healthtopics.html">Health Topics</a></li>
<li><a href="https://medlineplus.gov/druginformation.html">Drugs & Supplements</a></li>
<li><a href="https://medlineplus.gov/genetics/">Genetics</a></li>
<li><a href="https://medlineplus.gov/lab-tests/">Medical Tests</a></li>
<li><a href="https://medlineplus.gov/encyclopedia.html">Medical Encyclopedia</a></li>
<li><a href="https://medlineplus.gov/about/">About MedlinePlus</a></li>
</ul><button id="sm-search-btn" class="navmenu-btn" title="Search" role="button" aria-controls="mplus-search" type="submit"><span class="hide-offscreen"></span>Search<span class="icon icon-nav-search"></span></button>
<div class="top-1">
<form id="mplus-search" method="get" action="https://vsearch.nlm.nih.gov/vivisimo/cgi-bin/query-meta" title="Search MedlinePlus" target="_self">
<input type="hidden" name="v:project" value="medlineplus"/>
<input type="hidden" name="v:sources" value="medlineplus-bundle"/>
<div class="form-box text-combo">
<div class="form-area"><label class="hide-offscreen" for="searchtext_primary">Search MedlinePlus</label>
<input id="searchtext_primary" class="form-text" type="text" placeholder="Search MedlinePlus" alt="#Site Search input" title="Site Search input" maxlength="400" size="40" name="query" autocomplete="off" role="textbox" aria-autocomplete="list" aria-haspopup="true"/>
</div>
<div class="button-area">
<button class="form-btn" title="Search MedlinePlus" alt="Search MedlinePlus" type="submit">GO</button>
</div>
</div>
</form>
<div class="secondarynav">
<ul class="nav-list">
<li><a href="https://medlineplus.gov/about/"><span>About MedlinePlus</span></a></li>
<li><a href="https://medlineplus.gov/whatsnew/">What's New</a></li>
<li><a href="https://medlineplus.gov/sitemap.html"><span>Site Map</span></a></li>
<li><a href="https://support.nlm.nih.gov/knowledgebase/category/?id=CAT-01231&category=medlineplus&from=https%3A//medlineplus.gov/lab-tests/hemoglobin-a1c-hba1c-test/" target="_blank"><span>Customer Support</span></a></li>
</ul>
</div>
</div>
<div id="mplus-nav-bar">
<ul class="nav-list">
<li><a href="https://medlineplus.gov/healthtopics.html">Health Topics</a></li><li><a href="https://medlineplus.gov/druginformation.html">Drugs & Supplements</a></li><li><a href="https://medlineplus.gov/genetics/">Genetics</a></li><li><a href="https://medlineplus.gov/lab-tests/">Medical Tests</a></li><li><a href="https://medlineplus.gov/encyclopedia.html">Medical Encyclopedia</a></li>
</ul>
</div>
<a id="mplus-lang-toggle" href="https://medlineplus.gov/spanish/pruebas-de-laboratorio/prueba-de-hemoglobina-a1c/" title="Español">Español</a>
</div>
</div>
</header>
<div id="mplus-content">
<div id="breadcrumbs">
<div itemprop="breadcrumb" itemscope="" itemtype="http://schema.org/BreadcrumbList">
<span class="hide-offscreen">You Are Here:</span>
<div itemscope itemprop="itemListElement" itemtype="http://schema.org/ListItem">
<a href="https://medlineplus.gov/" itemprop="item"><span itemprop="name">Home</span></a>
&rarr;
<meta itemprop="position" content="1"/>
</div>
<div itemscope itemprop="itemListElement" itemtype="http://schema.org/ListItem">
<a href="https://medlineplus.gov/lab-tests/" itemprop="item"><span itemprop="name">Medical Tests</span></a>
&rarr;
<meta itemprop="position" content="2"/>
</div>
<div>
<span>Hemoglobin A1C (HbA1c) Test</span>
</div>
</div>
</div>
<span class="page-url print-only">URL of this page: https://medlineplus.gov/lab-tests/hemoglobin-a1c-hba1c-test/</span>
<div >
<article>
<div class="page-info">
<div class="page-title">
<a name="start" id="start"></a>
<h1>Hemoglobin A1C (HbA1c) Test</h1>
</div>
<div class="page-actions"></div>
<noscript><span class="js-disabled-message">To use the sharing features on this page, please enable JavaScript.</span></noscript>
</div>
<div class="main">
<section><div class="mp-content"><h2>What is a hemoglobin A1C (HbA1C) test?</h2>
<p>A hemoglobin <a data-tid="6308" href="https://medlineplus.gov/a1c.html">A1C</a> (HbA1C) test is a blood test that shows what your average <a data-tid="6121" href="https://medlineplus.gov/bloodglucose.html">blood sugar</a> (glucose) level was over the past two to three months.</p>
<p>Glucose is a type of sugar in your blood that comes from the foods you eat. Your cells use glucose for energy. A <a data-tid="1499" href="https://medlineplus.gov/hormones.html">hormone</a> called insulin helps glucose get into your cells. If you have <a data-tid="4" href="https://medlineplus.gov/diabetes.html">diabetes</a> your body doesn't make enough insulin, or your cells don't use it well. As a result, glucose can't get into your cells, so your blood sugar levels increase.</p>
<p>Glucose in your blood sticks to hemoglobin, a protein in your red blood cells. As your blood glucose levels increase, more of your hemoglobin will be coated with glucose. An A1C test measures the percentage of your red blood cells that have glucose-coated hemoglobin.</p>
<p>An A1C test can show your average glucose level for the past three months because:</p>
<ul>
<li>Glucose sticks to hemoglobin for as long as the red blood cells are alive.</li>
<li>Red blood cells live about three months.</li>
</ul>
<p>High A1C levels are a sign of high blood glucose from diabetes. Diabetes can cause <a data-tid="4567" href="https://medlineplus.gov/diabetescomplications.html">serious health problems</a>, including <a data-tid="6011" href="https://medlineplus.gov/diabeticheartdisease.html">heart disease</a>, <a data-tid="1559" href="https://medlineplus.gov/diabetickidneyproblems.html">kidney disease</a>, and <a data-tid="1465" href="https://medlineplus.gov/diabeticnerveproblems.html">nerve damage</a>. But with treatment and lifestyle changes, you can control your blood glucose levels.</p>
<p>Other names: HbA1C, A1C, glycohemoglobin, glycated hemoglobin, glycosylated hemoglobin</p></div>
</section>
<section><div class="mp-content"><h2>What is it used for?</h2>
<p>An A1C test may be used to <a data-tid="4482" href="https://medlineplus.gov/healthscreening.html">screen fo</a>r or diagnose:</p>
<ul>
<li><strong><a data-tid="5930" href="https://medlineplus.gov/diabetestype2.html">Type 2 diabetes</a>.</strong> With type 2 diabetes your blood glucose gets too high because your body doesn't make enough insulin to move blood sugar from your bloodstream into your cells, or because your cells stop responding to insulin.</li>
<li><strong><a data-tid="5784" href="https://medlineplus.gov/prediabetes.html">Prediabetes</a>.</strong> Prediabetes means that your blood glucose levels are higher than normal, but not high enough to diagnosed as diabetes. Lifestyle changes, such as <a data-tid="3048" href="https://medlineplus.gov/diabeticdiet.html">healthy eating</a> and <a data-tid="6601" href="https://medlineplus.gov/benefitsofexercise.html">exercise</a>, may help delay or prevent prediabetes from becoming type 2 diabetes.</li>
</ul>
<p>If you have diabetes or prediabetes, an A1C test can help monitor your condition and check how well you've been able to control your blood sugar levels.</p></div>
</section>
<section><div class="mp-content"><h2>Why do I need an HbA1C test?</h2>
<p>The Centers for Disease Control (CDC) recommends A1C testing for diabetes and prediabetes if:</p>
<ul>
<li><strong>You are over age 45.</strong>
<ul>
<li>If your results are normal, you should repeat the test every 3 years.</li>
<li>If your results show you have prediabetes, you will usually need to be tested every 1 to 2 years. Ask your provider how often to get tested and what you can do to reduce your risk of developing diabetes.</li>
<li>If your results show you have diabetes, you should get an A1C test at least twice a year to monitor your condition and treatment.</li>
</ul>
</li>
<li><strong>You are under 45 and are more likely to develop diabetes because you:</strong>
<ul>
<li>Have prediabetes.</li>
<li>Are overweight or have <a data-tid="61" href="https://medlineplus.gov/obesity.html">obesity</a>.</li>
<li>Have a parent or sibling with type 2 diabetes.</li>
<li>Have <a data-tid="34" href="https://medlineplus.gov/highbloodpressure.html">high blood pressure</a> or high <a data-tid="26" href="https://medlineplus.gov/cholesterol.html">cholesterol</a> levels.</li>
<li>Have <a data-tid="277" href="https://medlineplus.gov/heartdiseases.html">heart disease</a> or have had a <a data-tid="8" href="https://medlineplus.gov/stroke.html">stroke</a>.</li>
<li>Are <a data-tid="490" href="https://medlineplus.gov/exerciseandphysicalfitness.html">physically active</a> less than 3 times a week.</li>
<li>Have had <a data-tid="1408" href="https://medlineplus.gov/diabetesandpregnancy.html">gestational diabetes</a> (diabetes during pregnancy) or given birth to a baby over 9 pounds.</li>
<li>Are African American, Hispanic or Latino, American Indian, or an Alaska Native person. Some Pacific Islander and Asian American people also have a higher risk of developing diabetes.</li>
<li>Have <a data-tid="5912" href="https://medlineplus.gov/polycysticovarysyndrome.html">polycystic ovarian syndrome</a> (PCOS).</li>
</ul>
</li>
</ul>
<p>You may also need an A1C test if you have symptoms of diabetes, such as:</p>
<ul>
<li>Feeling very thirsty</li>
<li>Urinating (peeing) a lot</li>
<li>Losing weight without trying</li>
<li>Feeling very hungry</li>
<li>Blurred vision</li>
<li>Numb or tingling hands or feet</li>
<li><a data-tid="5324" href="https://medlineplus.gov/fatigue.html">Fatigue</a></li>
<li>Dry skin</li>
<li>Sores that heal slowly</li>
<li>Having more infections than usual</li>
</ul></div>
</section>
<section><div class="mp-content"><h2>What happens during an A1C test?</h2>
<p>A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.</p></div>
</section>
<section><div class="mp-content"><h2>Will I need to do anything to prepare for the test?</h2>
<p>You don't need any special preparations for an A1C test.</p></div>
</section>
<section><div class="mp-content"><h2>Are there any risks to the test? </h2>
<p>There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.</p></div>
</section>
<section><div class="mp-content"><h2>What do the results mean?</h2>
<p>A1C results tell you what percentage of your hemoglobin is coated with glucose. The percent ranges are just a guide to what is normal. What's normal for you depends on your health, age, and other factors. Ask your provider what A1C percentage is healthy for you.</p>
<p>To diagnose diabetes or prediabetes, the percentages commonly used are:</p>
<ul>
<li><strong>Normal:</strong> A1C below 5.7%</li>
<li><strong>Prediabetes:</strong> A1C between 5.7% and 6.4%</li>
<li><strong>Diabetes:</strong> A1C of 6.5% or higher</li>
</ul>
<p>Providers often use more than one test to diagnose diabetes. So, if your test result was higher than normal, you may have another A1C test or a <a data-pid="32945" href="https://medlineplus.gov/lab-tests/diabetes-tests/">different type of diabetes test</a>, usually either a fasting <a data-pid="690" href="https://medlineplus.gov/lab-tests/blood-glucose-test/">blood glucose test</a> or an oral glucose tolerance test (OGTT).</p>
<p>If your A1C test was done to monitor your diabetes, talk with your provider about what your test results mean.</p>
<p>Learn more about <a data-pid="806" href="https://medlineplus.gov/lab-tests/how-to-understand-your-lab-results/">laboratory tests, reference ranges, and understanding results</a>.</p></div>
</section>
<section><div class="mp-content"><h2>Is there anything else I need to know about an HbA1C test?</h2>
<p>The A1C test is not used to diagnose gestational diabetes or <a data-tid="1339" href="https://medlineplus.gov/diabetestype1.html">type 1 diabetes</a>.</p>
<p>Also, if you have a condition that affects your red blood cells, such as <a data-tid="139" href="https://medlineplus.gov/anemia.html">anemia</a> or another type of <a data-tid="3646" href="https://medlineplus.gov/blooddisorders.html">blood disorder</a>, an A1C test may not be accurate for diagnosing diabetes. <a data-tid="302" href="https://medlineplus.gov/kidneyfailure.html">Kidney failure</a> and <a data-tid="310" href="https://medlineplus.gov/liverdiseases.html">liver disease</a> can also affect A1C results. In these cases, your provider may recommend different tests to diagnose diabetes and prediabetes.</p></div>
</section>
<section><div class="mp-refs mp-content"><h2>References</h2>
<ol>
<li>American Diabetes Association [Internet]. Arlington (VA): American Diabetes Association; c1995–2022. Understanding A1C: A1C does it all; [ cited 2022 May 17]; [about 5 screens]. Available from: <a href="https://www.diabetes.org/diabetes/A1C" target="bibliowin">https://www.diabetes.org/diabetes/A1C</a></li>
<li>American Diabetes Association [Internet]. Arlington (VA): American Diabetes Association; c1995–2022. Common Terms; [cited 2022 May 17]; [about 57 screens]. Available from: <a href="https://diabetes.org/about-diabetes/common-terms" target="bibliowin">https://diabetes.org/about-diabetes/common-terms</a></li>
<li>Centers for Disease Control and Prevention [Internet]. Atlanta: U.S. Department of Health and Human Services; Testing for Diabetes and Prediabetes: A1C; [reviewed 2021 Aug 10; cited 2022 May 17]; [about 4 screens]. Available from: <a href="https://www.cdc.gov/diabetes/diabetes-testing/prediabetes-a1c-test.html" target="bibliowin">https://www.cdc.gov/diabetes/diabetes-testing/prediabetes-a1c-test.html</a></li>
<li>Centers for Disease Control and Prevention [Internet]. Atlanta: U.S. Department of Health and Human Services; Diabetes Risk Factors; [reviewed 2022 Apr 5;cited 2022 May 17]; [about 3 screens]. Available from: <a href="https://www.cdc.gov/diabetes/risk-factors/" target="bibliowin">https://www.cdc.gov/diabetes/risk-factors/</a></li>
<li>Mayo Clinic [Internet]. Mayo Foundation for Medical Education and Research; c1998–2022. A1c test; [cited 2022 May 17]; [about 7 screens]. Available from: <a href="https://www.mayoclinic.org/tests-procedures/a1c-test/about/pac-20384643" target="bibliowin">https://www.mayoclinic.org/tests-procedures/a1c-test/about/pac-20384643</a></li>
<li>Merck Manual Consumer Version [Internet]. Kenilworth (NJ): Merck &amp; Co. Inc.; c2022. Diabetes Mellitus (DM); [modified 2020 Sep; cited 2022 May 17]; [about 13 screens]. Available from: <a href="http://www.merckmanuals.com/home/hormonal-and-metabolic-disorders/diabetes-mellitus-dm-and-disorders-of-blood-sugar-metabolism/diabetes-mellitus-dm#v773034" target="bibliowin">http://www.merckmanuals.com/home/hormonal-and-metabolic-disorders/diabetes-mellitus-dm-and-disorders-of-blood-sugar-metabolism/diabetes-mellitus-dm#v773034</a></li>
<li>National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Blood Tests; [updated 2022 Mar 24; cited 2022 May 17]; [about 8 screens]. Available from: <a href="https://www.nhlbi.nih.gov/health-topics/blood-tests" target="bibliowin">https://www.nhlbi.nih.gov/health-topics/blood-tests</a></li>
<li>National Institute of Diabetes and Digestive and Kidney Diseases [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Diabetes Tests &amp; Diagnosis; [reviewed 2016 Dec; cited 2022 May 17]; [about 6 screens]. Available from: <a href="https://www.niddk.nih.gov/health-information/diabetes/overview/tests-diagnosis#who" target="bibliowin">https://www.niddk.nih.gov/health-information/diabetes/overview/tests-diagnosis#who</a></li>
<li>National Institute of Diabetes and Digestive and Kidney Diseases [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; The A1C Test &amp; Diabetes; [reviewed 2018 Apr; cited 2022 May 17]; [about 10 screens]. Available from: <a href="https://www.niddk.nih.gov/health-information/diagnostic-tests/a1c-test#affected" target="bibliowin">https://www.niddk.nih.gov/health-information/diagnostic-tests/a1c-test#affected</a></li>
<li>National Institute of Diabetes and Digestive and Kidney Diseases [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Insulin Resistance &amp; Prediabetes; [reviewed 2018 May; cited 2022 May 17]; [about 8 screens]. Available from: <a href="https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/prediabetes-insulin-resistance#develop" target="bibliowin">https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/prediabetes-insulin-resistance#develop</a></li>
<li>National Institute of Diabetes and Digestive and Kidney Diseases [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; What is Diabetes?; [reviewed 2016 Dec; cited 2022 May 17]; [about 4 screens]. Available from: <a href="https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes#types" target="bibliowin">https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes#types</a></li>
<li>Testing.com [Internet]. Seattle (WA).: OneCare Media; c2022. Hemoglobin A1c; [modified 2021 Nov 9; cited 2022 May 17]; [about 12 screens]. Available from: <a href="https://www.testing.com/tests/hemoglobin-a1c/" target="bibliowin">https://www.testing.com/tests/hemoglobin-a1c/</a></li>
<li>Testing.com [Internet]. Seattle (WA).: OneCare Media; c2022. Glucose Testing; [modified 2021 Nov 9; cited 2022 May 17]; [about 11 screens]. Available from: <a href="https://www.testing.com/glucose-testing/" target="bibliowin">https://www.testing.com/glucose-testing/</a></li>
<li>University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2022. Health Encyclopedia: A1C; [cited 2022 May 17]; [about 4 screens]. Available from: <a href="https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&amp;contentid;=A1C" target="bibliowin">https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&amp;contentid;=A1C</a></li>
<li>UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2022. Glycohemoglobin (HbA1c, A1c); [current 2021 Jul 28; cited 2022 May 17]; [about 8 screens]. Available from: <a href="https://patient.uwhealth.org/healthwise/article/en-us/hw8432" target="bibliowin">https://patient.uwhealth.org/healthwise/article/en-us/hw8432</a></li>
</ol></div>
</section>
</div>
<div class="side">
<aside>
<section><div class="side-section">
<div class="section-header">
<h2>Related Health Topics</h2>
</div>
<div class="section-body">
<ul class="relatedmp">
<li><a href="https://medlineplus.gov/a1c.html">A1C</a></li>
<li><a href="https://medlineplus.gov/bloodglucose.html">Blood Glucose</a></li>
<li><a href="https://medlineplus.gov/diabetes.html">Diabetes</a></li>
<li><a href="https://medlineplus.gov/diets.html">Diets</a></li>
<li><a href="https://medlineplus.gov/exerciseandphysicalfitness.html">Exercise and Physical Fitness</a></li>
<li><a href="https://medlineplus.gov/highbloodpressure.html">High Blood Pressure</a></li>
<li><a href="https://medlineplus.gov/obesity.html">Obesity</a></li>
<li><a href="https://medlineplus.gov/prediabetes.html">Prediabetes</a></li>
</ul>
</div>
</div></section>
<section><div class="side-section">
<div class="section-header">
<h2>Related Medical Tests</h2>
</div>
<div class="section-body">
<ul class="relatedmp">
<li><a href="https://medlineplus.gov/lab-tests/blood-glucose-test/">Blood Glucose Test</a></li>
<li><a href="https://medlineplus.gov/lab-tests/c-peptide-test/">C-Peptide Test</a></li>
<li><a href="https://medlineplus.gov/lab-tests/diabetes-tests/">Diabetes Tests</a></li>
<li><a href="https://medlineplus.gov/lab-tests/diabetic-foot-exam/">Diabetic Foot Exam</a></li>
<li><a href="https://medlineplus.gov/lab-tests/glucagon-blood-test/">Glucagon Blood Test</a></li>
<li><a href="https://medlineplus.gov/lab-tests/glucose-in-urine-test/">Glucose in Urine Test</a></li>
<li><a href="https://medlineplus.gov/lab-tests/how-to-cope-with-medical-test-anxiety/">How to Cope with Medical Test Anxiety</a></li>
<li><a href="https://medlineplus.gov/lab-tests/how-to-understand-your-lab-results/">How to Understand Your Lab Results</a></li>
<li><a href="https://medlineplus.gov/lab-tests/insulin-in-blood/">Insulin in Blood</a></li>
<li><a href="https://medlineplus.gov/lab-tests/ketones-in-blood/">Ketones in Blood</a></li>
<li><a href="https://medlineplus.gov/lab-tests/ketones-in-urine/">Ketones in Urine</a></li>
<li><a href="https://medlineplus.gov/lab-tests/what-you-need-to-know-about-blood-testing/">What You Need to Know About Blood Testing</a></li>
</ul>
</div>
</div></section>
</aside>
</div>
<div class="bottom">
<section><div class="lt-disclaimer">
<p>The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.</p>
</div>
</section>
</div>
</article>
</div>
<div id="citation-how-to">
<button><span>Learn how to cite this page</span></button>
</div>
</div>
<footer>
<div id="mplus-footer">
<div class="footer1">
<ul class="secondarynav">
<li><a href="https://medlineplus.gov/about/">About MedlinePlus</a></li>
<li><a href="https://medlineplus.gov/whatsnew/">What's New</a></li>
<li><a href="https://medlineplus.gov/sitemap.html">Site Map</a></li>
<li><a href="https://support.nlm.nih.gov/knowledgebase/category/?id=CAT-01231&category=medlineplus&from=https%3A//medlineplus.gov/lab-tests/hemoglobin-a1c-hba1c-test/" target="_blank"><span>Customer Support</span></a></li>
</ul>
<ul class="follow-footer">
<li>
<a href="https://medlineplus.gov/rss.html" class="follow-item">Subscribe to RSS<img src="https://medlineplus.gov/images/feed.png" class="social-media-toolkit-icon" alt="RSS" title="RSS"></a>
</li>
<li>
<span class="follow-label">Follow us</span>
<a href="https://twitter.com/medlineplus" class="follow-item" target="_blank">
<img src="https://medlineplus.gov/images/i_share_twitter.png" class="follow-icon" alt="X" title="X">
</a>
<a href="https://facebook.com/Mplus.gov/" class="follow-item" target="_blank">
<img src="https://medlineplus.gov/images/i_share_fb.png" class="follow-icon" alt="Facebook" title="Facebook">
</a>
<a href="https://www.instagram.com/mplusgov/" class="follow-item" target="_blank">
<img src="https://medlineplus.gov/images/Instagram_Glyph_Gradient_RGB.png" class="follow-icon" alt="Instagram" title="Instagram">
</a>
</li>
<li>
<a href="https://medlineplus.gov/social-media-toolkit/" class="social-media-toolkit-item">Social Media Toolkit<img src="https://medlineplus.gov/images/i_social_media_toolkit.png" class="social-media-toolkit-icon" alt="Social Media Toolkit" title="Social Media Toolkit"></a>
</li>
</ul>
</div>
<div class="footer2">
<ul>
<li><a href=" https://www.nlm.nih.gov/web_policies.html" target='_blank'>NLM Web Policies</a></li>
<li><a href="https://medlineplus.gov/about/using/usingcontent/" >Copyright</a></li>
<li><a href="https://medlineplus.gov/accessibility.html">Accessibility</a></li>
<li><a href="https://medlineplus.gov/about/using/criteria/">Guidelines for Links</a></li>
<li><a href="https://medlineplus.gov/plugins.html">Viewers & Players</a></li>
<li><a href="https://www.hhs.gov/vulnerability-disclosure-policy/index.html" target="_blank">HHS Vulnerability Disclosure</a></li>
<li><a href="https://medlineplus.gov/medlineplus-connect/">MedlinePlus Connect for EHRs</a></li>
<li><a href="https://medlineplus.gov/about/developers/">For Developers</a></li>
</ul>
<div class="address">
<a href="https://www.nlm.nih.gov" target="_blank">National Library of Medicine</a>
<span>8600 Rockville Pike, Bethesda, MD 20894</span>
<a href="https://www.hhs.gov" target="_blank">U.S. Department of Health and Human Services</a>
<a href="https://www.nih.gov" target="_blank">National Institutes of Health</a>
</div>
<div class="date">
<span id="lastupdate">Last updated September 6, 2022</span>
</div>
<div class="return-top"><a href="#top" title="Return to top"><img class="return-top-icon" alt="Return to top" src="https://medlineplus.gov/images/return-top.png"></a></div>
</div>
</div>
</footer>
</div>
<script src="https://medlineplus.gov/jslib/jquery-3.6.0.min.js" type="text/javascript"></script>
<script src="https://medlineplus.gov/jslib/mplus-frontend-controls-new.js" type="text/javascript"></script>
<script src="https://medlineplus.gov/jslib/mplus-share.js?id=1112022" type="text/javascript"></script>
<!--[if lte IE 9]><script src="//www.nlm.nih.gov/medlineplus/jslib/jquery.placeholder.js" type="text/javascript"></script><![endif]-->
<script src="https://medlineplus.gov/jslib/control.js" type="text/javascript"></script>
<script src="https://medlineplus.gov/uswds/js/uswds.min.js" type="text/javascript"></script>
<script type='application/ld+json'>{
"@context": "http://schema.org",
"@type": "MedicalWebPage",
"headline": "Hemoglobin A1C (HbA1c) Test",
"description": "A hemoglobin A1C (HbA1C) test is a blood test that shows what your average blood sugar (glucose) level was over the past two to three months. Glucose is a type of sugar in your blood that comes from the foods you eat. Your cells use glucose for energy. A hormone called insulin helps glucose get into your cells. If you have diabetes your body doesn't make enough insulin, or your cells don't use it well. As a result, glucose can't get into your cells, so your blood sugar levels increase. Glucose in your blood sticks to hemoglobin, a protein in your red blood cells. As your blood glucose levels increase, more of your hemoglobin will be coated with glucose. An A1C test measures the percentage of your red blood cells that have glucose-coated hemoglobin. An A1C test can show your average glucose level for the past three months because: Glucose sticks to hemoglobin for as long as the red blood cells are alive.; Red blood cells live about three months.; High A1C levels are a sign of high blood glucose from diabetes. Diabetes can cause serious health problems, including heart disease, kidney disease, and nerve damage. But with treatment and lifestyle changes, you can control your blood glucose levels. Other names: HbA1C, A1C, glycohemoglobin, glycated hemoglobin, glycosylated hemoglobin",
"url": "https://medlineplus.gov/lab-tests/hemoglobin-a1c-hba1c-test/",
"publisher": {
"@type": "Organization",
"legalName": "National Library of Medicine",
"url": "https://www.nlm.nih.gov",
"brand": {
"@type": "Brand",
"name": "MedlinePlus",
"description": "MedlinePlus is an online health information resource for patients and their families and friends. It is a service of the National Library of Medicine (NLM), the world's largest medical library, and a part of the National Institutes of Health (NIH).",
"url": "https://medlineplus.gov",
"logo": {
"@type": "ImageObject",
"url": "https://medlineplus.gov/images/m_logo_primary.png"
}
},
"parentOrganization": {
"@type": "Organization",
"legalName": "National Institutes of Health",
"url": "https://www.nih.gov"
}
}
}</script>
</body>
</html>
Reference in a new issue View git blame Copy permalink