nih-gov/medlineplus.gov/ency/article/000773.htm
2025-02-26 13:17:41 -05:00

295 lines
No EOL
32 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="article" class="nojs us" data-root="//medlineplus.gov" itemid="https://medlineplus.gov/ency/article/000773.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/000773.htm" itemprop="url"/>
<link rel="alternative" hreflang="es" href="https://medlineplus.gov/spanish/ency/article/000773.htm"/>
<link rel="alternative" hreflang="en" href="https://medlineplus.gov/ency/article/000773.htm"/><meta property="og:title" content="Bell palsy: MedlinePlus Medical Encyclopedia"/><meta property="og:url" content="https://medlineplus.gov/ency/article/000773.htm"/><meta property="twitter:title" content="Bell palsy: MedlinePlus Medical Encyclopedia"/><meta name="twitter:card" content="summary_large_image"/><meta name="description" content="Bell palsy is a disorder of the nerve that controls movement of the muscles in the face. This nerve is called the facial or seventh cranial nerve."/><meta itemprop="description" name="description" content="Bell palsy is a disorder of the nerve that controls movement of the muscles in the face. This nerve is called the facial or seventh cranial nerve."/><meta property="og:description" content="Bell palsy is a disorder of the nerve that controls movement of the muscles in the face. This nerve is called the facial or seventh cranial nerve."/><meta property="twitter:description" content="Bell palsy is a disorder of the nerve that controls movement of the muscles in the face. This nerve is called the facial or seventh cranial nerve."/><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>Bell palsy: 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/000773.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/000773.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>Bell palsy</span></div></div>
<span class="page-url print-only">URL of this page: //medlineplus.gov/ency/article/000773.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">Bell palsy</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>Bell palsy is a disorder of the nerve that controls movement of the muscles in the face. This nerve is called the facial or seventh cranial nerve.</p><p>Damage to this nerve causes weakness or paralysis of these muscles. <a test="test" href="./003028.htm">Paralysis</a> means that you cannot use the muscles at all.</p></div><section><div class="section"><div class="section-header"><div class="section-title"><h2>Causes</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>Bell palsy can affect people of any age, most commonly those over age 65 years. It can also affect children younger than 10 years. Males and females are equally affected.</p><p>Bell palsy is thought to be due to <a test="test" href="./003103.htm">swelling</a> (inflammation) of the facial nerve in the area where it travels through the bones of the skull. This nerve controls movement of the muscles of the face.</p><p>The cause is often not clear. A type of herpes infection called herpes simplex or <a test="test" href="./000858.htm">herpes zoster</a> might be involved. Other conditions that may affect the seventh cranial nerve include:</p><ul><li><a test="test" href="./000594.htm">HIV/AIDS</a> infection
</li><li><a test="test" href="./001319.htm">Lyme disease</a></li><li>Middle <a test="test" href="./001336.htm">ear infection</a></li><li><a test="test" href="./000076.htm">Sarcoidosis</a> (inflammation of the lymph nodes, lungs, liver, eyes, skin, or other tissues)</li></ul><p>Having diabetes and being pregnant may increase the risk for Bell palsy.</p></div></div></section><section><div class="section"><div class="section-header"><div class="section-title"><h2>Symptoms</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>Sometimes, you may have a cold shortly before the symptoms of Bell palsy begin.</p><p>Symptoms most often start suddenly, but may take 2 to 3 days to become fully developed. They do not become more severe after that.</p><p>Symptoms are almost always on one side of the face only. They may range from mild to severe.</p><p>Many people feel discomfort behind the ear before weakness is noticed. The face feels stiff or pulled to one side and may look different. Other signs can include:</p><ul><li>Difficulty closing one eye</li><li>Difficulty eating and drinking because food falls out of one side of the mouth</li><li><a test="test" href="./003048.htm">Drooling</a> due to lack of control over the muscles of the face</li><li>Slurring your words (dysarthria) due to lip weakness</li><li>Drooping of the face, such as the eyelid or corner of the mouth</li><li>Problems smiling, grimacing, or making facial expressions</li><li>Twitching or weakness of the muscles in the face </li></ul><p>Other symptoms that may occur:</p><ul><li>Dry eye, which may lead to eye sores or infections</li><li>Dry mouth</li><li>Headache if there is an infection such as Lyme disease</li><li><a test="test" href="./003050.htm">Loss of sense of taste</a></li><li>Sound that is louder in one ear (hyperacusis)</li></ul></div></div></section><section><div class="section"><div class="section-header"><div class="section-title"><h2>Exams and Tests</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>Often, Bell palsy can be diagnosed just by taking a health history and doing a complete physical exam.</p><p>Blood tests may be done to look for medical problems such as Lyme disease, which may cause Bell palsy. </p><p>Sometimes, a test is needed to check the nerves that supply the muscles of the face:</p><ul><li><a test="test" href="./003929.htm">Electromyography</a> (EMG) to check the health of the facial muscles and the nerves that control the muscles</li><li><a test="test" href="./003927.htm">Nerve conduction test</a> to check how fast electrical signals move through a nerve</li></ul><p>If your health care provider is worried there is another cause for your symptoms, they may suggest:</p><ul><li><a test="test" href="./003786.htm">CT scan of the head</a></li><li><a test="test" href="./003791.htm">Magnetic resonance imaging (MRI) of the head</a></li><li><a test="test" href="./003428.htm">Lumbar puncture</a> (spinal tap)</li></ul></div></div></section><section><div class="section"><div class="section-header"><div class="section-title"><h2>Treatment</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>Often, no treatment is needed. Symptoms often begin to improve right away. But, it may take weeks or even months for the muscles to get stronger.</p><p>Your provider may give you lubricating eye drops or eye ointments to keep the surface of the eye moist if you can't close it completely. You may need to wear an eye patch while you sleep.</p><p>Often, medicines may be used to improve the chances of recovery, but they must be started right away. Common medicines are:</p><ul><li>Corticosteroids, which may reduce swelling around the facial nerve</li><li>Medicines such as valacyclovir to fight the virus that may be causing Bell palsy</li></ul><p>Surgery to relieve pressure on the nerve (decompression surgery) has not been shown to benefit most people with Bell palsy.</p></div></div></section><section><div class="section"><div class="section-header"><div class="section-title"><h2>Outlook (Prognosis)</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>Most cases go away completely within a few weeks to months.</p><p>If you did not lose all of your nerve function and symptoms began to improve within 3 weeks, you are more likely to regain all or most of the strength in your facial muscles.</p><p>Sometimes, the following symptoms may still be present:</p><ul><li>Long-term changes in taste</li><li>Spasms of muscles or eyelids</li><li>Weakness that remains in facial muscles </li></ul></div></div></section><section><div class="section"><div class="section-header"><div class="section-title"><h2>Possible Complications</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>Complications may include:</p><ul><li>Eye surface becoming dry, leading to eye sores, infections, and vision loss</li><li>Swelling in the muscles due to loss of nerve function</li></ul></div></div></section><section><div class="section"><div class="section-header"><div class="section-title"><h2>When to Contact a Medical Professional</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>Contact your provider right away if your face droops or you have other symptoms of Bell palsy. Your provider can rule out other, more serious conditions, such as stroke.</p></div></div></section><section><div class="section"><div class="section-header"><div class="section-title"><h2>Prevention</h2></div><div class="section-button"><button type="submit" aria-controls="section-8" 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-8"><p>There is no known way to prevent Bell palsy.</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>Facial palsy; Idiopathic peripheral facial palsy; Cranial mononeuropathy - Bell palsy; Bell's palsy</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/9101t.jpg" alt="Facial drooping" title="Facial drooping" class="side-img"/><a href="../imagepages/9101.htm">Facial drooping</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>National Institute of Neurological Disorders and Stroke website. Bell's palsy. <a href="https://www.ninds.nih.gov/health-information/disorders/bells-palsy" target="_blank">www.ninds.nih.gov/health-information/disorders/bells-palsy</a>. Updated May 2, 2024. Accessed July 1, 2024.</p><p>Ryan MM. Bell palsy. In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. <em>Nelson Textbook of Pediatrics</em>. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 657.</p><p>Smith G, Shy ME. Peripheral neuropathies. In: Goldman L, Cooney KA, eds. <em>Goldman-Cecil Medicine</em>. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 388.</p><p>Wallenstein J. Brain and cranial nerve disorders. In: Walls RM, ed. <em>Rosen's Emergency Medicine: Concepts and Clinical Practice</em>. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 91.</p></div></div></section>
<section><div class="section"><div class="section-header"><div class="section-title"><h2>Review Date 6/13/2024</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: Joseph V. Campellone, MD, Department of Neurology, Cooper Medical School at Rowan University, Camden, NJ. Review provided by VeriMed Healthcare Network. 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/bellspalsy.html">Bell's Palsy</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>