nih-gov/medlineplus.gov/ency/article/003330.htm
2025-02-26 13:17:41 -05:00

292 lines
No EOL
32 KiB
HTML
Raw 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="article" class="nojs us" data-root="//medlineplus.gov" itemid="https://medlineplus.gov/ency/article/003330.htm" itemtype="http://schema.org/MedicalWebPage" itemscope="">
<head>
<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 charset="utf-8"/>
<meta property="fb:app_id" content="1042245625821448"/>
<meta name="expires" content="Wed, 05 02 2025"/>
<meta name="ac-dictionary" content="medlineplus-ac-dictionary"/>
<link rel="shortcut icon" href="https://medlineplus.gov/images/favicon.ico" type="image/x-icon"/>
<link rel="apple-touch-icon" href="//medlineplus.gov/images/touch-icon.png"/>
<meta name="viewport" content="width=device-width, initial-scale=1"/>
<link rel="stylesheet" href="https://medlineplus.gov/css/common_new.css?04272023"/>
<!--[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"/>
<link rel="stylesheet" href="https://medlineplus.gov/css/ency/ency2.css?07162024"/>
<script type="text/javascript">document.querySelector("html").className = document.querySelector("html").className.replace(/nojs[\s]*/g, '');</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'?'&amp;l='+l:'';j.async=true;j.src='//www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-MMVM77');</script>
<link rel="canonical" href="https://medlineplus.gov/ency/article/003330.htm" itemprop="url"/>
<link rel="alternative" hreflang="es" href="https://medlineplus.gov/spanish/ency/article/003330.htm"/>
<link rel="alternative" hreflang="en" href="https://medlineplus.gov/ency/article/003330.htm"/><meta property="og:title" content="CT scan: MedlinePlus Medical Encyclopedia"/><meta property="og:url" content="https://medlineplus.gov/ency/article/003330.htm"/><meta property="twitter:title" content="CT scan: MedlinePlus Medical Encyclopedia"/><meta name="twitter:card" content="summary_large_image"/><meta name="description" content="A computed tomography (CT) scan is an imaging method that uses x-rays to create pictures of cross-sections of the body."/><meta itemprop="description" name="description" content="A computed tomography (CT) scan is an imaging method that uses x-rays to create pictures of cross-sections of the body."/><meta property="og:description" content="A computed tomography (CT) scan is an imaging method that uses x-rays to create pictures of cross-sections of the body."/><meta property="twitter:description" content="A computed tomography (CT) scan is an imaging method that uses x-rays to create pictures of cross-sections of the body."/><meta property="og:image" content="https://medlineplus.gov/images/share_ency_1.jpg"/><meta property="og:image" content="https://medlineplus.gov/images/share_ency_2.jpg"/><meta property="og:image" content="https://medlineplus.gov/images/share_ency_3.jpg"/><meta property="twitter:image" content="https://medlineplus.gov/images/share_ency_1.jpg"/>
<title>CT scan: MedlinePlus Medical Encyclopedia</title>
</head>
<body><link href="http://schema.org/Patient" itemprop="audience"/>
<!-- Google Tag Manager -->
<noscript><iframe title="googletagmanager" src="//www.googletagmanager.com/ns.html?id=GTM-MMVM77" height="0" width="0" style="display:none;visibility:hidden">
</iframe>
</noscript>
<!-- End Google Tag Manager -->
<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">Heres 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">Heres 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">
</path>
</svg> </span>) or <strong>https://</strong> means youve 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">
<!-- Orgs
================================================== -->
<div id="mplus-orgs">
<a title="National Institutes of Health" target="_blank" class="nih-org" href="//www.nih.gov/">
<img alt="National Institutes of Health" src="https://medlineplus.gov/images/nihlogo.png" class="nihlogo"/>
</a><a target="_blank" href="https://www.nlm.nih.gov/"> National Library of Medicine </a>
</div>
<!-- Logo
================================================== -->
<div id="mplus-logo" class="years-25">
<a href="https://medlineplus.gov">
<img src="https://medlineplus.gov/images/m_logo_25.png" title="MedlinePlus Trusted Health Information for You" alt="MedlinePlus Trusted Health Information for You"/>
</a>
</div>
<!-- Nav Menu
================================================== -->
<div id="mplus-nav">
<div class="sm-live-area hide-offscreen" aria-live="polite">The navigation menu has been collapsed.</div>
<!-- Menu Button-->
<button type="submit" aria-controls="mplus-menu-list" role="button" title="Menu" class="navmenu-btn" id="sm-menu-btn" aria-pressed="false" tabindex="0">Menu<span class="icon icon-nav-menu">
</span></button><ul class="nav-list" id="mplus-menu-list">
<li><a href="https://medlineplus.gov/healthtopics.html">Health Topics</a></li>
<li><a href="https://medlineplus.gov/druginformation.html">Drugs &amp; 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 type="submit" aria-controls="mplus-search" role="button" title="Search" class="navmenu-btn" id="sm-search-btn" aria-pressed="false" tabindex="0"><span class="hide-offscreen">Show </span>Search<span class="icon icon-nav-search">
</span></button>
<div class="top-1">
<!-- Search
================================================== -->
<form target="_self" title="Search MedlinePlus" action="//vsearch.nlm.nih.gov/vivisimo/cgi-bin/query-meta" method="get" id="mplus-search">
<input type="hidden" value="medlineplus" name="v:project"/>
<input type="hidden" value="medlineplus-bundle" name="v:sources"/>
<div class="form-box text-combo">
<div class="form-area"><label for="searchtext_primary" class="hide-offscreen">Search MedlinePlus</label>
<span role="status" aria-live="polite" class="ui-helper-hidden-accessible">
</span><input type="text" aria-haspopup="true" aria-autocomplete="list" role="textbox" autocomplete="off" name="query" size="40" maxlength="400" title="Site Search input" alt="Site Search input" placeholder="Search MedlinePlus" class="form-text ui-autocomplete-input" id="searchtext_primary"/>
</div>
<div class="button-area">
<button type="submit" alt="Search MedlinePlus" title="Search MedlinePlus" class="form-btn">GO</button>
</div>
</div>
</form>
<!-- Secondary Nav
================================================== -->
<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/"><span>What's New</span></a></li>
<li><a href="https://medlineplus.gov/sitemap.html"><span>Site Map</span></a></li>
<li><a target="_blank" href="https://support.nlm.nih.gov/knowledgebase/category/?id=CAT-01231&amp;category=medlineplus&amp;from=//medlineplus.gov/ency/article/003330.htm"><span>Customer Support</span></a></li>
</ul>
</div>
</div>
<!-- Nav Bar
================================================== -->
<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 &amp; 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 title="Español" id="mplus-lang-toggle" href="../../spanish/ency/article/003330.htm">Español</a>
</div>
</div>
</header>
<!-- Content
================================================== -->
<div id="mplus-content">
<!-- Breadrcumbs -->
<div id="breadcrumbs"><div itemtype="http://schema.org/BreadcrumbList" itemscope="" itemprop="breadcrumb"><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/encyclopedia.html" itemprop="item"><span itemprop="name">Medical Encyclopedia</span></a>
&rarr;
<meta itemprop="position" content="2"/>
</div>
</div><div><span>CT scan</span></div></div>
<span class="page-url print-only">URL of this page: //medlineplus.gov/ency/article/003330.htm
</span>
<!-- Article -->
<article><div id="d-article"><div class="page-info"><div class="page-title"><a name="start" id="start">
</a><h1 class="with-also" itemprop="name">CT scan</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"><div id="ency_summary"><p>A computed tomography (CT) scan is an imaging method that uses x-rays to create pictures of cross-sections of the body.</p><p>Related tests include:</p><ul><li><a test="test" href="./003789.htm">Abdominal and pelvis CT scan</a></li><li><a test="test" href="./003786.htm">Cranial or head CT scan</a></li><li>Cervical, thoracic, and <a test="test" href="./003787.htm">lumbosacral spine CT scan</a></li><li><a test="test" href="./003785.htm">Orbit CT scan</a></li><li><a test="test" href="./003788.htm">Chest CT scan</a></li><li>CT angiogram</li></ul></div><section><div class="section"><div class="section-header"><div class="section-title"><h2>How the Test is Performed</h2></div><div class="section-button"><button type="submit" aria-controls="section-1" role="button" title="Expand/Collapse section"><span class="icon icon-section-action">
</span></button></div><div class="sm-live-area hide-offscreen" aria-live="polite">
</div></div><div class="section-body" id="section-1"><p>You will be asked to lie on a narrow table that slides into the center of the CT scanner.</p><p>Once you are inside the scanner, the machine's x-ray beam rotates around you. Modern spiral scanners can perform the exam without stopping. There is very little noise.</p><p>A computer creates separate images of the body area, called slices. These images can be stored, viewed on a monitor, or copied to a disk. Three-dimensional models of the body area can be created by stacking the slices together.</p><p>You must stay still during the exam, because movement causes blurred images. You may be told to hold your breath for short periods of time.</p><p>Complete scans most often take only a few minutes. The newest scanners can image your entire body in less than 30 seconds.</p><img title="CT scan" alt="CT scan" src="//medlineplus.gov/ency/images/ency/fullsize/23213.jpg" class="img-e" itemprop="image"/></div></div></section><section><div class="section"><div class="section-header"><div class="section-title"><h2>How to Prepare for the Test</h2></div><div class="section-button"><button type="submit" aria-controls="section-2" role="button" title="Expand/Collapse section"><span class="icon icon-section-action">
</span></button></div><div class="sm-live-area hide-offscreen" aria-live="polite">
</div></div><div class="section-body" id="section-2"><p>Certain exams require a special dye, called contrast, to be delivered into your body before the test starts. Contrast helps certain areas show up better on the x-rays.</p><p>Let your health care provider know if you have ever had a reaction to contrast. You may need to take medicines before the test in order to avoid another reaction.</p><p>Contrast can be given several ways, depending on the type of CT being performed.</p><ul><li>It may be delivered through a vein (IV) in your hand or forearm.</li><li>You might drink the contrast before your scan. When you drink the contrast depends on the type of exam being done. The contrast liquid may taste chalky, although some are flavored. The contrast passes out of your body through your stools.</li><li>Rarely, the contrast may be given into your rectum using an enema. </li></ul><p>If contrast is used, you may also be asked not to eat or drink anything for 4 to 6 hours before the test.</p><p>Before receiving IV contrast, tell your provider if you take the diabetes medicine metformin (Glucophage). People taking this medicine may need to stop temporarily. Also let your provider know if you have any problems with your kidneys. The IV contrast can worsen kidney function.</p><p>Find out if the CT machine has a weight limit if you weigh more than 300 pounds (135 kilograms). Too much weight can damage the scanner.</p><p>You will need to remove jewelry and wear a gown during the study.</p></div></div></section><section><div class="section"><div class="section-header"><div class="section-title"><h2>How the Test will Feel</h2></div><div class="section-button"><button type="submit" aria-controls="section-3" role="button" title="Expand/Collapse section"><span class="icon icon-section-action">
</span></button></div><div class="sm-live-area hide-offscreen" aria-live="polite">
</div></div><div class="section-body" id="section-3"><p>Some people may have discomfort from lying on the hard table.</p><p>Contrast given through an IV may cause a slight burning feeling, a metallic taste in the mouth, and a warm flushing of the body. These sensations are normal and usually go away within a few seconds.</p></div></div></section><section><div class="section"><div class="section-header"><div class="section-title"><h2>Why the Test is Performed</h2></div><div class="section-button"><button type="submit" aria-controls="section-4" role="button" title="Expand/Collapse section"><span class="icon icon-section-action">
</span></button></div><div class="sm-live-area hide-offscreen" aria-live="polite">
</div></div><div class="section-body" id="section-4"><p>A CT scan creates detailed pictures of the body, including the brain, chest, spine, and abdomen. The test may be used to:</p><ul><li>Diagnose an infection</li><li>Guide a doctor to the right area during a biopsy</li><li>Identify masses and tumors, including cancer</li><li>Study blood vessels </li></ul></div></div></section><section><div class="section"><div class="section-header"><div class="section-title"><h2>Normal Results</h2></div><div class="section-button"><button type="submit" aria-controls="section-5" role="button" title="Expand/Collapse section"><span class="icon icon-section-action">
</span></button></div><div class="sm-live-area hide-offscreen" aria-live="polite">
</div></div><div class="section-body" id="section-5"><p>Results are considered normal if the organs and structures being examined are normal in appearance.</p></div></div></section><section><div class="section"><div class="section-header"><div class="section-title"><h2>What Abnormal Results Mean</h2></div><div class="section-button"><button type="submit" aria-controls="section-6" role="button" title="Expand/Collapse section"><span class="icon icon-section-action">
</span></button></div><div class="sm-live-area hide-offscreen" aria-live="polite">
</div></div><div class="section-body" id="section-6"><p>Abnormal results depend on the part of the body being studied. Talk to your provider about questions and concerns.</p></div></div></section><section><div class="section"><div class="section-header"><div class="section-title"><h2>Risks</h2></div><div class="section-button"><button type="submit" aria-controls="section-7" role="button" title="Expand/Collapse section"><span class="icon icon-section-action">
</span></button></div><div class="sm-live-area hide-offscreen" aria-live="polite">
</div></div><div class="section-body" id="section-7"><p>Risks of having CT scans include:</p><ul><li>Allergic reaction to the contrast dye</li><li>Damage to kidney function from the contrast dye</li><li>Exposure to radiation </li></ul><p>CT scans expose you to more radiation than regular x-rays. Having many x-rays or CT scans over time may increase your risk for cancer. However, the risk from any one scan is small. You and your provider should weigh this risk against the value of the information that will come from a CT scan. Most new CT scan machines have the ability to reduce the radiation dose.</p><p>Some people have allergies to contrast dye. Let your provider know if you have ever had an allergic reaction to injected contrast dye.</p><ul><li>The most common type of contrast given into a vein contains iodine. If you have an iodine allergy, contrast may cause <a test="test" href="./003117.htm">nausea or vomiting</a>, <a test="test" href="./003060.htm">sneezing</a>, <a test="test" href="./003217.htm">itching</a>, or <a test="test" href="./000845.htm">hives</a>.</li><li>If you absolutely must be given such contrast, your provider may give you antihistamines (such as Benadryl) or steroids before the test.</li><li>Your kidneys help remove iodine from the body. You may need to receive extra fluids after the test to help flush iodine out of your body if you have diabetes or kidney disease.</li></ul><p>Rarely, the dye may cause a life-threatening allergic response called <a test="test" href="./000844.htm">anaphylaxis</a>. If you have any trouble breathing during the test, tell the scanner operator immediately. Scanners come with an intercom and speakers, so the operator can hear you at all times.</p></div></div></section><section><div class="section"><div class="section-header"><div class="section-title"><h2>Alternative Names</h2></div><div class="section-button"><button type="submit" aria-controls="section-Alt" role="button" title="Expand/Collapse section"><span class="icon icon-section-action">
</span></button></div><div class="sm-live-area hide-offscreen" aria-live="polite">
</div></div><div class="section-body" id="section-Alt"><p>CAT scan; Computed axial tomography scan; Computed tomography scan</p></div></div></section><section><div class="section sec-mb"><div class="section-header"><div class="section-title"><h2>Images</h2></div><div class="section-button"><button type="submit" aria-controls="section-tnails" role="button" title="Expand/Collapse section"><span class="icon icon-section-action">
</span></button></div><div class="sm-live-area hide-offscreen" aria-live="polite">
</div></div><div name="Images" class="section-body" id="section-tnails"><ul class="img-grid group">
<li><img src="//medlineplus.gov/ency/images/ency/tnails/23213t.jpg" alt="CT scan" title="CT scan" class="side-img"/><a href="../imagepages/1088.htm">CT scan</a></li>
</ul></div></div></section><section><div class="section"><div class="section-header"><div class="section-title"><h2>References</h2></div><div class="section-button"><button type="submit" aria-controls="section-Ref" role="button" title="Expand/Collapse section"><span class="icon icon-section-action">
</span></button></div><div class="sm-live-area hide-offscreen" aria-live="polite">
</div></div><div class="section-body" id="section-Ref"><p>Blankensteijn JD, Lely RJ. Computed tomography. In: Sidawy AN, Perler BA, eds. <em>Rutherford's Vascular Surgery and Endovascular Therapy</em>. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 29.</p><p>Levine MS, Gore RM. Diagnostic imaging procedures in gastroenterology. In: Goldman L, Schafer AI, eds. <em>Goldman-Cecil Medicine</em>. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 124.</p><p>Van Thielen T, van den Hauwe L, Van Goethem JW, Parizel PM.Current status of imaging of the spine and anatomical features. In: Adam A, Dixon AK, Gillard JH, Schaefer-Prokop CM, eds. <em>Grainger &amp; Allison's Diagnostic Radiology: A Textbook of Medical Imaging</em>. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 47.</p></div></div></section>
<section><div class="section"><div class="section-header"><div class="section-title"><h2>Review Date 7/5/2022</h2></div><div class="section-button"><button type="submit" aria-controls="section-version" role="button" title="Expand/Collapse section"><span class="icon icon-section-action">
</span></button></div><div class="sm-live-area hide-offscreen" aria-live="polite">
</div></div>
<div id="section-version" class="section-body"><p>Updated by: Jason Levy, MD, FSIR, Northside Radiology Associates, Atlanta, GA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.</p>
</div></div></section><section><div class="section ency-citation"><div class="section-header"><div class="section-title ency-citation"><div id="citation-how-to"><button><span>Learn how to cite this page</span></button></div></div><div class="sm-live-area hide-offscreen" aria-live="polite">
</div></div></div></section><section><div class="section sec-mb"><div class="section-header"><div class="section-title"><h2>Related MedlinePlus Health Topics</h2></div><div class="section-button"><button type="submit" aria-controls="section-mtp" role="button" title="Expand/Collapse section"><span class="icon icon-section-action">
</span></button></div><div class="sm-live-area hide-offscreen" aria-live="polite">
</div></div><div name="Related MedlinePlus Health Topics" class="section-body" id="section-mtp"><ul class="side-nav"><li><a href="https://medlineplus.gov/ctscans.html">CT Scans</a></li>
</ul></div></div></section></div></div></article>
</div>
<footer>
<div class="provider-box group">
<div class="urac-logo">
<a href="https://accreditnet.urac.org/directory/#/certification/HCP-2/info"><img src="https://medlineplus.gov/images/CertifiedSeal.png"/></a>
<p class="urac-logo-info">Health Content Provider<br>06/01/2025</p>
</div>
<p class="adam-info">
<a href='javascript:urac_open();'>A.D.A.M., Inc. is accredited by URAC</a>, for Health Content Provider (www.urac.org). URAC's <a href='javascript:hwsopen();'>accreditation program</a> is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s <a href='javascript:edpolopen();'>editorial policy, editorial process</a>, and <a href='javascript:ppopen();'>privacy policy</a>. A.D.A.M. is also a founding member of Hi-Ethics. This site complies with the HONcode standard for trustworthy health information: <a href='javascript:honc_open();'>verify here</a>.
</p>
</div>
<p class="adam-info">
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997-2025 A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
</p>
<div class="adam-logo">
<a href="https://www.adam.com/about" target="_blank"><img width="49" height="10" alt="About A.D.A.M." src="https://medlineplus.gov/ency/images/ency/ftrAdamlogo.gif"/></a>
</div>
<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 name="contact" target="_blank" href="https://support.nlm.nih.gov/knowledgebase/category/?id=CAT-01231&amp;category=medlineplus&amp;from="><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="//medlineplus.gov/accessibility.html">Accessibility</a></li>
<li><a href="https://medlineplus.gov/about/using/criteria/">Guidelines for Links</a></li>
<li><a href="//medlineplus.gov/plugins.html">Viewers &amp; 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="//www.nlm.nih.gov" target="_blank">National Library of Medicine</a>
<span>8600 Rockville Pike, Bethesda, MD 20894</span>
<a href="//www.hhs.gov" target="_blank">U.S. Department of Health and Human Services</a>
<a href="//www.nih.gov" target="_blank">National Institutes of Health</a>
</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><!-- End Wrap -->
<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.js" type="text/javascript">
</script>
<!--[if lte IE 9]>
<script src="https://medlineplus.gov/jslib/jquery.placeholder.js" type="text/javascript"></script>
<![endif]-->
<script src="https://medlineplus.gov/jslib/mplus-share.js?id=1112022" type="text/javascript">
</script>
<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 src="https://medlineplus.gov/jslib/ency/ency.js" type="text/javascript">
</script>
</body>
</html>