286 lines
No EOL
32 KiB
HTML
286 lines
No EOL
32 KiB
HTML
<!DOCTYPE html>
|
||
<html lang="en" id="article" class="nojs us" data-root="//medlineplus.gov" itemid="https://medlineplus.gov/ency/article/000821.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'?'&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/000821.htm" itemprop="url"/>
|
||
<link rel="alternative" hreflang="es" href="https://medlineplus.gov/spanish/ency/article/000821.htm"/>
|
||
<link rel="alternative" hreflang="en" href="https://medlineplus.gov/ency/article/000821.htm"/><meta property="og:title" content="Immune response: MedlinePlus Medical Encyclopedia"/><meta property="og:url" content="https://medlineplus.gov/ency/article/000821.htm"/><meta property="twitter:title" content="Immune response: MedlinePlus Medical Encyclopedia"/><meta name="twitter:card" content="summary_large_image"/><meta name="description" content="The immune response is how your body recognizes and defends itself against bacteria, viruses, and substances that appear foreign and harmful."/><meta itemprop="description" name="description" content="The immune response is how your body recognizes and defends itself against bacteria, viruses, and substances that appear foreign and harmful."/><meta property="og:description" content="The immune response is how your body recognizes and defends itself against bacteria, viruses, and substances that appear foreign and harmful."/><meta property="twitter:description" content="The immune response is how your body recognizes and defends itself against bacteria, viruses, and substances that appear foreign and harmful."/><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>Immune response: 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">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">
|
||
</path>
|
||
</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">
|
||
<!-- 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 & 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&category=medlineplus&from=//medlineplus.gov/ency/article/000821.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 & 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/000821.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>
|
||
→
|
||
<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>
|
||
→
|
||
<meta itemprop="position" content="2"/>
|
||
</div>
|
||
</div><div><span>Immune response</span></div></div>
|
||
<span class="page-url print-only">URL of this page: //medlineplus.gov/ency/article/000821.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">Immune response</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>The immune response is how your body recognizes and defends itself against bacteria, viruses, and substances that appear foreign and harmful.</p></div><section><div class="section"><div class="section-header"><div class="section-title"><h2>Information</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>The immune system protects the body from possibly harmful substances by recognizing and responding to <a test="test" href="./002224.htm">antigens</a>. Antigens are substances (usually proteins) on the surface of cells, viruses, fungi, or bacteria. Nonliving substances such as <a test="test" href="./002331.htm">toxins</a>, chemicals, drugs, and foreign particles (such as a splinter) can also be antigens. The immune system recognizes and destroys, or tries to destroy, substances that contain antigens.</p><p>Your body's cells have proteins that are antigens. These include a group of antigens called <a test="test" href="./003550.htm">HLA antigens</a>. Your immune system learns to see these antigens as normal and usually does not react against them.</p><p>INNATE IMMUNITY</p><p>Innate, or nonspecific, immunity is the defense system with which you were born. It protects you against all antigens. Innate immunity involves barriers that keep harmful materials from entering your body. These barriers form the first line of defense in the immune response. Examples of innate immunity include:</p><ul><li><a test="test" href="./003072.htm">Cough</a> reflex</li><li>Enzymes in tears and skin oils</li><li>Mucus, which traps bacteria and small particles</li><li>Skin</li><li>Stomach acid </li></ul><p>Innate immunity also comes in a protein chemical form, called innate humoral immunity. Examples include the body's complement system and substances called interferon and interleukin-1 (which causes fever).</p><p>If an antigen gets past these barriers, it is attacked and destroyed by other parts of the immune system.</p><p>ACQUIRED IMMUNITY</p><p>Acquired immunity is immunity that develops with exposure to various antigens. Your immune system builds a defense against that specific antigen. Vaccines work by causing acquired immunity without needing to have the infection first.</p><p>PASSIVE IMMUNITY</p><p>Passive immunity is due to <a test="test" href="./002223.htm">antibodies</a> that are produced in a body other than your own. Infants have passive immunity because they are born with antibodies that are transferred through the placenta from their mother. These antibodies disappear between ages 6 and 12 months.</p><p>Passive immunization may also be due to injection of antiserum, which contains antibodies that are formed by another person or animal. It provides immediate protection against an antigen, but does not provide long-lasting protection. Immune serum globulin (given for hepatitis exposure) and <a test="test" href="./000615.htm">tetanus</a> antitoxin are examples of passive immunization.</p><p>BLOOD COMPONENTS</p><p>The immune system includes certain types of white blood cells. It also includes chemicals and proteins in the blood, such as antibodies, complement proteins, and interferon. Some of these directly attack foreign substances in the body, and others work together to help the immune system cells.</p><p>Lymphocytes are a type of white blood cell. There are B and T type lymphocytes.</p><ul><li>B lymphocytes become cells that produce antibodies. Antibodies attach to a specific antigen and make it easier for the immune cells to destroy the antigen.</li><li>T lymphocytes attack antigens directly and help control the immune response. They also release chemicals, known as cytokines, which control the entire immune response. </li></ul><p>As lymphocytes develop, they normally learn to tell the difference between your own body tissues and substances that are not normally found in your body. Once B cells and T cells are formed, a few of those cells will multiply and provide "memory" for your immune system. This allows your immune system to respond faster and more efficiently the next time you are exposed to the same antigen. In many cases, it will prevent you from getting sick. For example, a person who has had chickenpox or has been immunized against chickenpox is immune from getting chickenpox again.</p><div class="videobox"><div class="group"><img class="rollover_globals" alt="Immune response" title="Immune response" src="//medlineplus.gov/ency/images/ency/tnails/200095t.gif"/>Watch this video about:<a class="blk" href="../anatomyvideos/000073.htm">Immune response</a></div></div><p>INFLAMMATION</p><p>The inflammatory response (inflammation) occurs when tissues are injured by bacteria, trauma, toxins, heat, or any other cause. The damaged cells release chemicals including histamine, bradykinin, and prostaglandins. These chemicals cause blood vessels to leak fluid into the tissues, causing <a test="test" href="./003103.htm">swelling</a>. This helps isolate the foreign substance from further contact with body tissues.</p><p>The chemicals also attract white blood cells called phagocytes that "eat" germs and dead or damaged cells. This process is called phagocytosis. Phagocytes eventually die. Pus is formed from a collection of dead tissue, dead bacteria, and live and dead phagocytes.</p><div class="videobox"><div class="group"><img class="rollover_globals" alt="Phagocytosis" title="Phagocytosis" src="//medlineplus.gov/ency/images/ency/tnails/200096t.gif"/>Watch this video about:<a class="blk" href="../anatomyvideos/000098.htm">Phagocytosis</a></div></div><p>IMMUNE SYSTEM DISORDERS AND ALLERGIES</p><p>Immune system disorders occur when the immune response is directed against body tissue, is excessive (this causes auto-immune disorders such as rheumatoid arthritis), or is lacking (causing immunodeficiency and increased risk of infections). <a test="test" href="./000812.htm">Allergies</a> involve an immune response to a substance that most people's bodies perceive as harmless.</p><p>IMMUNIZATION</p><p>Vaccination (<a test="test" href="./002024.htm">immunization</a>) is a way to trigger the immune response. Small doses of an antigen, such as dead or weakened live viruses or parts of a virus, are given to activate immune system "memory" (activated B cells and sensitized T cells). Memory allows your body to react quickly and efficiently to future exposures.</p><div class="videobox"><div class="group"><img class="rollover_globals" alt="Vaccines" title="Vaccines" src="//medlineplus.gov/ency/images/ency/tnails/200097t.gif"/>Watch this video about:<a class="blk" href="../anatomyvideos/000137.htm">Vaccines</a></div></div><p>COMPLICATIONS DUE TO AN ALTERED IMMUNE RESPONSE</p><p>An efficient immune response protects against many diseases and disorders. An inefficient immune response allows diseases to develop. Too much, too little, or the wrong immune response causes immune system disorders. An overactive immune response can lead to the development of <a test="test" href="./000816.htm">autoimmune diseases</a>, in which antibodies form against the body's own tissues. </p><p>Complications from altered immune responses include:</p><ul><li>Allergy or hypersensitivity</li><li><a test="test" href="./000844.htm">Anaphylaxis</a>, a life-threatening allergic reaction</li><li>Autoimmune disorders</li><li><a test="test" href="./001309.htm">Graft versus host disease</a>, a complication of a bone marrow transplant</li><li>Immunodeficiency disorders</li><li><a test="test" href="./000820.htm">Serum sickness</a></li><li>Transplant rejection </li></ul></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>Innate immunity; Humoral immunity; Cellular immunity; Immunity; Inflammatory response; Acquired (adaptive) immunity</p></div></div></section><section><div class="section sec-mb"><div class="section-header"><div class="section-title"><h2>Patient Instructions</h2></div><div class="section-button"><button type="submit" aria-controls="section-carepnt" 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="Patient Instructions" class="section-body" id="section-carepnt"><ul class="side-nav"><li><a href="../patientinstructions/000249.htm">Colds and the flu - what to ask your doctor - adult</a></li>
|
||
<li><a href="../patientinstructions/000250.htm">Colds and the flu - what to ask your doctor - child</a></li>
|
||
<li><a href="../patientinstructions/000319.htm">When your baby or infant has a fever</a></li>
|
||
</ul></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/8932t.jpg" alt="Immune system structures" title="Immune system structures" class="side-img"/><a href="../imagepages/8932.htm">Immune system structures</a></li>
|
||
<li><img src="//medlineplus.gov/ency/images/ency/tnails/9478t.jpg" alt="Phagocytosis" title="Phagocytosis" class="side-img"/><a href="../imagepages/9478.htm">Phagocytosis</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>Abbas AK, Lichtman AH, Pillai S. Properties and overview of immune responses. In: Abbas AK, Lichtman AH, Pillai S, eds. <em>Cellular and Molecular Immunology</em>. 10th ed. Philadelphia, PA: Elsevier; 2022:chap 1.</p><p>Bankova L, Barrett N. Innate immunity. In: Burks AW, Holgate ST, O'Hehir RE, et al, eds. <em>Middleton's Allergy: Principles and Practice</em>. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 1.</p><p>Salmon JE. Tissue injury and repair. In: Goldman L, Cooney KA, eds. <em>Goldman-Cecil Medicine</em>. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 36.</p><p>Tuano KS, Chinen J. Adaptive immunity. In: Burks AW, Holgate ST, O'Hehir RE, et al, eds. <em>Middleton's Allergy: Principles and Practice</em>. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 2.</p></div></div></section>
|
||
<section><div class="section"><div class="section-header"><div class="section-title"><h2>Review Date 3/31/2024</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: Deborah Pedersen, MD, MS, Allergy & Asthma Care, PC, Taunton, MA. 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/immunesystemanddisorders.html">Immune System and Disorders</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&category=medlineplus&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 & 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> |