677 lines
39 KiB
HTML
677 lines
39 KiB
HTML
|
||
<!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/prothrombin-time-test-and-inr-ptinr/" />
|
||
|
||
|
||
|
||
|
||
<link rel="alternate" hreflang="en" href="https://medlineplus.gov/lab-tests/prothrombin-time-test-and-inr-ptinr/" />
|
||
<link rel="alternate" hreflang="es" href="https://medlineplus.gov/spanish/pruebas-de-laboratorio/prueba-de-tiempo-de-protrombina-e-inr-tpinr/" />
|
||
|
||
|
||
|
||
|
||
<meta name="ac-dictionary" content="medlineplus-ac-dictionary" />
|
||
|
||
<meta name="description" content="A prothrombin time test with an INR (PT/INR) measures how long it takes blood to clot. It's used to diagnose and manage bleeding and clotting disorders." />
|
||
|
||
|
||
|
||
<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="Prothrombin Time Test and INR (PT/INR): MedlinePlus Medical Test" />
|
||
<meta property="og:url" content="https://medlineplus.gov/lab-tests/prothrombin-time-test-and-inr-ptinr/" />
|
||
|
||
|
||
|
||
<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 prothrombin time test with an INR (PT/INR) measures how long it takes blood to clot. It's used to diagnose and manage bleeding and clotting disorders." />
|
||
|
||
|
||
<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="Prothrombin Time Test and INR (PT/INR): MedlinePlus Medical Test" />
|
||
<meta name="twitter:description" content="A prothrombin time test with an INR (PT/INR) measures how long it takes blood to clot. It's used to diagnose and manage bleeding and clotting disorders." />
|
||
<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>Prothrombin Time Test and INR (PT/INR): MedlinePlus Medical Test</title>
|
||
|
||
<link rel="stylesheet" href="https://medlineplus.gov/css/common_new.css?1738957220818" />
|
||
<!--[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/prothrombin-time-test-and-inr-ptinr/" 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-tiempo-de-protrombina-e-inr-tpinr/" 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>
|
||
→
|
||
<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>
|
||
→
|
||
<meta itemprop="position" content="2"/>
|
||
</div>
|
||
|
||
|
||
|
||
<div>
|
||
<span>Prothrombin Time Test and INR (PT/INR)</span>
|
||
</div>
|
||
|
||
|
||
</div>
|
||
</div>
|
||
<span class="page-url print-only">URL of this page: https://medlineplus.gov/lab-tests/prothrombin-time-test-and-inr-ptinr/</span>
|
||
|
||
<div >
|
||
|
||
<article>
|
||
<div class="page-info">
|
||
<div class="page-title">
|
||
<a name="start" id="start"></a>
|
||
<h1>Prothrombin Time Test and INR (PT/INR)</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 prothrombin time test with an INR (PT/INR)?</h2>
|
||
<p>A prothrombin time (PT) test measures how many seconds it takes for a clot to form in a blood sample. Since the results of this test can vary with different labs or test methods, your results may be used to create an INR (international normalized ratio). Using this ratio makes it easier for health care providers to compare and better understand results from different labs or test methods.</p>
|
||
<p>Prothrombin is a protein made by the liver. It is one of several substances known as clotting (coagulation) factors. When you get a cut or other injury that causes bleeding, your clotting factors work together to form a blood clot. Blood clotting is an important process that prevents you from losing too much blood when you are injured. Clotting factor levels that are too low can cause you to <a data-tid="166" href="https://medlineplus.gov/bleedingdisorders.html">bleed too much</a> after an injury. Levels that are too high can cause dangerous <a data-tid="6076" href="https://medlineplus.gov/bloodclots.html">clots</a> to form in your arteries or veins.</p>
|
||
<p>A PT/INR test helps find out if your blood is clotting normally. It also checks to see if a medicine that prevents blood clots is working the way it should.</p>
|
||
<p>Other names: prothrombin time/international normalized ratio, PT, pro time</p></div>
|
||
</section>
|
||
|
||
<section><div class="mp-content"><h2>What is it used for?</h2>
|
||
<p>A PT/INR test is most often used to:</p>
|
||
<ul>
|
||
<li>See how well warfarin, an anti-coagulant or <a data-tid="4861" href="https://medlineplus.gov/bloodthinners.html">blood-thinning medicine</a>, is working to prevent blood clots. (Coumadin is a common brand name for warfarin.) Your provider may change your dose based on these results.</li>
|
||
<li>Find out the reason for abnormal blood clots.</li>
|
||
<li>Find out the reason for unusual bleeding.</li>
|
||
<li>Check clotting ability before a procedure or surgery that may cause bleeding.</li>
|
||
<li>Check for <a data-tid="310" href="https://medlineplus.gov/liverdiseases.html">liver problems</a>.</li>
|
||
<li>Check for <a data-tid="5388" href="https://medlineplus.gov/vitamink.html">vitamin K</a> deficiency. Vitamin K helps with blood clotting.</li>
|
||
</ul>
|
||
<p>A PT/INR test is often done along with a <a data-pid="1389" href="https://medlineplus.gov/lab-tests/partial-thromboplastin-time-ptt-test/">partial thromboplastin time (PTT) test</a>. A PTT test also checks for clotting problems but looks at different coagulation factors than the PT test.</p></div>
|
||
</section>
|
||
|
||
<section><div class="mp-content"><h2>Why do I need a PT/INR test?</h2>
|
||
<p>If you are regularly taking warfarin, you may need this test to make sure you are taking the right dose. Your provider will let you know how often you need to get the test to monitor your dose.</p>
|
||
<p>If you are not taking warfarin, you may need this test if you have symptoms of a bleeding or clotting disorder.</p>
|
||
<p>Symptoms of a bleeding disorder include:</p>
|
||
<ul>
|
||
<li>Unexplained heavy bleeding</li>
|
||
<li><a data-tid="1621" href="https://medlineplus.gov/bruises.html">Bruising</a> easily</li>
|
||
<li>Unusually heavy nose bleeds</li>
|
||
<li>Unusually heavy <a data-tid="325" href="https://medlineplus.gov/menstruation.html">menstrual periods</a> in women</li>
|
||
</ul>
|
||
<p>Symptoms of a clotting disorder include:</p>
|
||
<ul>
|
||
<li>Leg pain or tenderness</li>
|
||
<li><a data-tid="1229" href="https://medlineplus.gov/edema.html">Leg swelling</a></li>
|
||
<li>Redness or darkening of the skin on the leg</li>
|
||
<li>Skin that feels warm</li>
|
||
<li><a data-tid="3077" href="https://medlineplus.gov/breathingproblems.html">Trouble breathing</a></li>
|
||
<li><a data-tid="1543" href="https://medlineplus.gov/cough.html">Cough</a></li>
|
||
<li><a data-tid="4744" href="https://medlineplus.gov/chestpain.html">Chest pain</a></li>
|
||
<li>Rapid heartbeat and breathing</li>
|
||
</ul>
|
||
<p>In addition, you may need a PT/INR test if you are scheduled for surgery. It helps make sure your blood is clotting normally, so you won't lose too much blood during the procedure.</p></div>
|
||
</section>
|
||
|
||
<section><div class="mp-content"><h2>What happens during a PT/INR test?</h2>
|
||
<p>The test may be done on a blood sample from a vein or a fingertip.</p>
|
||
<p><strong>For a blood sample from a vein:</strong></p>
|
||
<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>
|
||
<p><strong>For a blood sample from a fingertip:</strong></p>
|
||
<p>A fingertip test may be done in a provider's office or in your home. If you have been taking warfarin for a long time, you may be trained to take your blood sample with an <a data-pid="31381" href="https://medlineplus.gov/lab-tests/at-home-medical-tests/">at-home testing kit</a>. Your provider may recommend you test your blood regularly using an at-home PT/INR test kit. During this test, you or your provider will:</p>
|
||
<ul>
|
||
<li>Use a small needle to puncture your fingertip.</li>
|
||
<li>Collect a drop of blood and place it onto a test strip or other special instrument.</li>
|
||
<li>Place the instrument or test strip into a device that calculates the results. At-home devices are small and lightweight.</li>
|
||
</ul>
|
||
<p>If you are using an at-home test kit, you will need to review your results with your provider. Your provider will let you know how they would like to receive the results.</p></div>
|
||
</section>
|
||
|
||
<section><div class="mp-content"><h2>Will I need to do anything to prepare for the test?</h2>
|
||
<p>If you are taking warfarin, you may need to delay your daily dose until after testing. Your provider will let you know if there are any other special instructions to follow.</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>If you were tested because you are taking warfarin or have certain health conditions, your results will probably be in the form of INR levels:</p>
|
||
<ul>
|
||
<li>INR levels that are <strong>too low</strong> may mean you are at risk for dangerous blood clots because your blood clots too easily.</li>
|
||
<li>INR levels that are <strong>too high</strong> may mean you are at risk for dangerous bleeding because your blood is taking longer than normal to form a clot.</li>
|
||
</ul>
|
||
<p>If your INR is not normal, your provider will probably change your dose of warfarin.</p>
|
||
<p>If you are not taking warfarin, your results may be in the form of a PT time, which is the number of seconds it takes for your blood sample to clot (prothrombin time).</p>
|
||
<p>If you are not taking warfarin and your INR or prothrombin time results are not normal, it may be a sign of that your blood is not clotting normally.</p>
|
||
<ul>
|
||
<li>If your PT/INR levels are <strong>too low</strong>, your blood is clotting too quickly. This may be due to:
|
||
<ul>
|
||
<li>A clotting disorder, a condition in which your body forms too many clots in arteries or veins. Clots can form when you don't have an injury, or they don't dissolve when they should.</li>
|
||
<li>Supplements with vitamin K, or a diet high in vitamin K.</li>
|
||
<li>Certain medicines.</li>
|
||
</ul>
|
||
</li>
|
||
<li>If your PT/INR levels are <strong>too high</strong>, your blood is clotting too slowly. This may be due to:
|
||
<ul>
|
||
<li>A bleeding disorder, a condition in which your body can't clot blood well. When you have an injury or a procedure that may cause bleeding, it may cause too much bleeding.</li>
|
||
<li>Liver disease.</li>
|
||
<li>Vitamin K deficiency. Vitamin K plays an important role in blood clotting.</li>
|
||
</ul>
|
||
</li>
|
||
</ul>
|
||
<p>Be sure to tell your provider if you are taking any medicines or supplements. Some may affect your results. Other things that may affect your PT/INR results include:</p>
|
||
<ul>
|
||
<li>Alcohol</li>
|
||
<li>Foods high in vitamin K, such as green leafy vegetables</li>
|
||
<li>Soybean and canola oils</li>
|
||
<li>High-fat diets</li>
|
||
</ul>
|
||
<p>Ask your provider what you should avoid before your PT/INR test.</p>
|
||
<p>To understand the results of a PT/INR test, your provider will consider your symptoms, medical history, and the results of other blood tests.</p>
|
||
<p>Learn more about laboratory tests, reference ranges, and understanding results.</p></div>
|
||
</section>
|
||
|
||
<section><div class="mp-content"><h2>Is there anything else I need to know about a PT/INR test?</h2>
|
||
<p>Sometimes certain liver tests are ordered along with a PT/INR test. These include:</p>
|
||
<ul>
|
||
<li><a data-pid="654" href="https://medlineplus.gov/lab-tests/ast-test/">Aspartate Aminotransferase (AST)</a></li>
|
||
<li><a data-pid="754" href="https://medlineplus.gov/lab-tests/alt-blood-test/">Alanine Aminotransferase (ALT)</a></li>
|
||
</ul></div>
|
||
</section>
|
||
|
||
<section><div class="mp-refs mp-content"><h2>References</h2>
|
||
<ol>
|
||
<li>American Society of Hematology [Internet]. Washington D.C.: American Society of Hematology; c2023. Blood Clots; [cited 2023 Nov 21]; [about 3 screens]. Available from: <a href="https://www.hematology.org/education/patients/blood-clots" target="bibliowin">https://www.hematology.org/education/patients/blood-clots</a></li>
|
||
<li>Cleveland Clinic: Health Library: Diagnostics & Testing [Internet]. Cleveland (OH): Cleveland Clinic; c2023. Blood Tests; [reviewed 2022 Dec 06; cited 2023 Nov 21]; [about 16 screens]. Available from: <a href="https://my.clevelandclinic.org/health/diagnostics/24508-blood-tests" target="bibliowin">https://my.clevelandclinic.org/health/diagnostics/24508-blood-tests</a></li>
|
||
<li>Labcorp [Internet]. Burlington (NC): Laboratory Corporation of America(r) Holdings; c2023. Patient Test Information: Prothrombin Time (PT); [cited 2024 Feb 08]; [about 8 screens]. Available from: <a href="https://www.labcorp.com/tests/005199/prothrombin-time-pt" target="bibliowin">https://www.labcorp.com/tests/005199/prothrombin-time-pt</a></li>
|
||
<li>Labpedia.net [Internet].c.2014-2024. Prothrombin Time (PT); [cited 2024 Feb 08]; [about 11 screens]. Available from: <a href="https://labpedia.net/prothombin-time-pt/" target="bibliowin">https://labpedia.net/prothombin-time-pt/</a></li>
|
||
<li>Mayo Clinic [Internet]. Mayo Foundation for Medical Education and Research; c1998-2023. Prothrombin time test: Overview; 2022 Nov 30 [cited 2023 Nov 21]; [about 9 screens]. Available from: <a href="https://www.mayoclinic.org/tests-procedures/prothrombin-time/about/pac-20384661" target="bibliowin">https://www.mayoclinic.org/tests-procedures/prothrombin-time/about/pac-20384661</a></li>
|
||
<li>Merck Manual Consumer Version [Internet]. Kenilworth (NJ): Merck & Co., Inc.; c2023.Vitamin K Deficiency; [reviewed 2022 Nov; cited 2024 Feb 08]; [about 3 screens]. Available from: <a href="https://www.merckmanuals.com/home/disorders-of-nutrition/vitamins/vitamin-k-deficiency" target="bibliowin">https://www.merckmanuals.com/home/disorders-of-nutrition/vitamins/vitamin-k-deficiency</a></li>
|
||
<li>National Blood Clot Alliance: Stop the Clot [Internet]. Gaithersburg (MD): National Blood Clot Alliance; INR Self-Testing; [cited 2023 Nov 11]; [about 14 screens]. Available from: <a href="https://www.stoptheclot.org/about-clots/blood-clot-treatment/warfarin/inr-self-testing" target="bibliowin">https://www.stoptheclot.org/about-clots/blood-clot-treatment/warfarin/inr-self-testing</a></li>
|
||
<li>National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; What Are Bleeding Disorders; [updated 2023 Aug 3; cited 2023 Nov 21]; [about 3 screens]. Available from: <a href="https://www.nhlbi.nih.gov/health/bleeding-disorders" target="bibliowin">https://www.nhlbi.nih.gov/health/bleeding-disorders</a></li>
|
||
<li>National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; What Are Blood Clotting Disorders?; [updated 2022 Mar 24; cited 2024 Feb 9]; [about 2 screens]. Available from: <a href="https://www.nhlbi.nih.gov/health/clotting-disorders" target="bibliowin">https://www.nhlbi.nih.gov/health/clotting-disorders</a></li>
|
||
<li>Nemours KidsHealth [Internet]. Jacksonville (FL): The Nemours Foundation; c1995-2023. Blood Test: Prothrombin Time (PT); [reviewed 2021 Sep; cited 2023 Nov 21]; [about 3 screens]. Available from: <a href="https://kidshealth.org/en/parents/test-pt.html" target="bibliowin">https://kidshealth.org/en/parents/test-pt.html</a></li>
|
||
<li>Nemours KidsHealth [Internet]. Jacksonville (FL): The Nemours Foundation; c1995-2023. Getting a Blood Test; [reviewed 2021 Sep; cited 2024 Feb 09]; [about 4 screens]. Available from: <a href="https://kidshealth.org/en/parents/blood-tests.html" target="bibliowin">https://kidshealth.org/en/parents/blood-tests.html</a></li>
|
||
<li>Pathology Tests Explained [Internet]. Alexandria (Australia): Australasian Association for Clinical Biochemistry and Laboratory Medicine; c2023. International normalized ration (INR); [reviewed 2023 Jun 01; cited 2024 Feb 8]; [about 8 screens]. Available from: <a href="https://pathologytestsexplained.org.au/ptests-pro.php?q=International+normalised+ratio+%28INR%29" target="bibliowin">https://pathologytestsexplained.org.au/ptests-pro.php?q=International+normalised+ratio+%28INR%29</a></li>
|
||
<li>Shikdar S, Vashisht R, Bhattacharya PT. International Normalized Ratio (INR). 2023 May 1. [cited 2024 Feb 8] In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. PMID: 29939529.</li>
|
||
<li>Testing.com [Internet]. Seattle (WA): OneCare Media; c2023. PTT Blood Test (Partial Thromboplastin Time); [modified 2021 Nov 9; cited 2023 Nov 21]; [about 16 screens]. Available from: <a href="https://www.testing.com/tests/partial-thromboplastin-time-ptt-aptt/" target="bibliowin">https://www.testing.com/tests/partial-thromboplastin-time-ptt-aptt/</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/bleedingdisorders.html">Bleeding Disorders</a></li>
|
||
|
||
|
||
<li><a href="https://medlineplus.gov/bloodclots.html">Blood Clots</a></li>
|
||
|
||
|
||
<li><a href="https://medlineplus.gov/bloodthinners.html">Blood Thinners</a></li>
|
||
|
||
|
||
<li><a href="https://medlineplus.gov/deepveinthrombosis.html">Deep Vein Thrombosis</a></li>
|
||
|
||
|
||
<li><a href="https://medlineplus.gov/hemophilia.html">Hemophilia</a></li>
|
||
|
||
|
||
<li><a href="https://medlineplus.gov/liverdiseases.html">Liver Diseases</a></li>
|
||
|
||
|
||
<li><a href="https://medlineplus.gov/pulmonaryembolism.html">Pulmonary Embolism</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/alt-blood-test/">ALT Blood Test</a></li>
|
||
|
||
|
||
<li><a href="https://medlineplus.gov/lab-tests/ast-test/">AST Test</a></li>
|
||
|
||
|
||
<li><a href="https://medlineplus.gov/lab-tests/at-home-medical-tests/">At-Home Medical Tests</a></li>
|
||
|
||
|
||
<li><a href="https://medlineplus.gov/lab-tests/coagulation-factor-tests/">Coagulation Factor Tests</a></li>
|
||
|
||
|
||
<li><a href="https://medlineplus.gov/lab-tests/d-dimer-test/">D-Dimer 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/liver-function-tests/">Liver Function Tests</a></li>
|
||
|
||
|
||
<li><a href="https://medlineplus.gov/lab-tests/partial-thromboplastin-time-ptt-test/">Partial Thromboplastin Time (PTT) Test</a></li>
|
||
|
||
|
||
<li><a href="https://medlineplus.gov/lab-tests/platelet-tests/">Platelet Tests</a></li>
|
||
|
||
|
||
<li><a href="https://medlineplus.gov/lab-tests/protein-c-and-protein-s-tests/">Protein C and Protein S Tests</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/prothrombin-time-test-and-inr-ptinr/" 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 May 15, 2024</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": "Prothrombin Time Test and INR (PT/INR)",
|
||
"description": "A prothrombin time (PT) test measures how many seconds it takes for a clot to form in a blood sample. Since the results of this test can vary with different labs or test methods, your results may be used to create an INR (international normalized ratio). Using this ratio makes it easier for health care providers to compare and better understand results from different labs or test methods. Prothrombin is a protein made by the liver. It is one of several substances known as clotting (coagulation) factors. When you get a cut or other injury that causes bleeding, your clotting factors work together to form a blood clot. Blood clotting is an important process that prevents you from losing too much blood when you are injured. Clotting factor levels that are too low can cause you to bleed too much after an injury. Levels that are too high can cause dangerous clots to form in your arteries or veins. A PT/INR test helps find out if your blood is clotting normally. It also checks to see if a medicine that prevents blood clots is working the way it should. Other names: prothrombin time/international normalized ratio, PT, pro time",
|
||
"url": "https://medlineplus.gov/lab-tests/prothrombin-time-test-and-inr-ptinr/",
|
||
"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>
|