This content does not have an English version.
This content does not have an Arabic version.
Mayo Clinic
  • Request an Appointment
  • Find a Doctor
  • Find a Job
  • Give Now
  • Log in to Patient Account
  • English
    • Español
    • العربية
    • 简体中文
  • Twitter
  • Facebook
  • Pinterest
  • YouTube
  • English
    • Español
    • العربية
    • 简体中文
mayo-mobile-logo-image
  • Menu
  • Search
All Mayo Clinic Topics
  • Care at Mayo Clinic
    • Overview
    • Appointments
    • Locations
    • Patient & Visitor Guide
    • International Services
    • Medical Departments & Centers
    • Doctors & Medical Staff
    • Patient Online Services
    • Billing & Insurance
    • Clinical Trials
    • International Business Collaborations
    • About Mayo Clinic
    • Contact Us
  • Health Information
    • Overview
    • Diseases & Conditions A-Z
    • Symptoms A-Z
    • Tests & Procedures A-Z
    • Drugs & Supplements A-Z
    • Health Books
    • Healthy Living Program
    • Mayo Clinic Health Letter
    • Mayo Clinic Voice Apps
    • Healthy Lifestyle

    Featured conditions

    Brain tumor, breast cancer, colon cancer, congenital heart disease, heart arrhythmia. See more conditions.
  • For Medical Professionals
    • Overview
    • Provider Relations
    • CareLink Online Referrals
    • Continuing Medical Education
    • Mayo Clinic Laboratories
    • AskMayoExpert
    • Video Center
    • Journals and Publications
  • Research
    • Overview
    • Research Faculty
    • Laboratories
    • Core Facilities
    • Centers & Programs
    • Departments & Divisions
    • Clinical Trials
    • Institutional Review Board
    • Postdoctoral Fellowships
    • Training Grant Programs
  • College of Medicine and Science
    • Overview
    • Mayo Clinic Graduate School of Biomedical Sciences
    • Mayo Clinic Alix School of Medicine
    • Mayo Clinic School of Continuous Professional Development
    • Mayo Clinic School of Graduate Medical Education
    • Mayo Clinic School of Health Sciences
  • Giving to Mayo Clinic
    • Overview
    • Give Now
    • Philanthropy in Action
    • Frequently Asked Questions
    • Contact Us to Give

About This Site

Who we are

  • Accreditations and awards - Who we areAccreditations and awards
  • Meet our medical editors - Who we areMeet our medical editors
  • Content development policy - Who we areContent development policy

Our policies

  • Advertising and sponsorship policy - Our policiesAdvertising and sponsorship policy
  • Corrections policy - Our policiesCorrections policy
  • Guidelines for sites linking to MayoClinic.org - Our policiesGuidelines for sites linking to MayoClinic.org
  • Privacy policy - Our policiesPrivacy policy
  • Content development policy - Our policiesContent development policy
  • Reprint permissions - Our policiesReprint permissions
  • Terms and conditions of use policy - Our policiesTerms and conditions of use policy

Business opportunities

  • Advertising and sponsorship - Business opportunitiesAdvertising and sponsorship
  • About Mayo Clinic - Business opportunitiesAbout Mayo Clinic

Media resources

  • Contacts - Media resourcesContacts
  • About Mayo Clinic - Media resourcesAbout Mayo Clinic
RSS feeds

RSS feeds

Subscribe to MayoClinic.org RSS feeds

Advertisement

Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission.

Advertising & Sponsorship
  • Policy
  • Opportunities
  • Ad Choices

Mayo Clinic Press

Check out these best-sellers and special offers on books and newsletters from Mayo Clinic Press.

  • Mayo Clinic on Incontinence - Mayo Clinic PressMayo Clinic on Incontinence
  • NEW – The Essential Diabetes Book - Mayo Clinic PressNEW – The Essential Diabetes Book
  • NEW – Mayo Clinic on Hearing and Balance - Mayo Clinic PressNEW – Mayo Clinic on Hearing and Balance
  • FREE Mayo Clinic Diet Assessment - Mayo Clinic PressFREE Mayo Clinic Diet Assessment
  • Mayo Clinic Health Letter - FREE book - Mayo Clinic PressMayo Clinic Health Letter - FREE book
.
  1. Home
  2. About This Site

Mayo Clinic Footer

  • Request Appointment
  • Symptom Checker
  • Give Now
  • Contact Us
  • About Mayo Clinic
  • Employees
  • Site Map
  • About This Site

Legal Conditions and Terms

Any use of this site constitutes your agreement to the Terms and Conditions and Privacy Policy linked below.

  • Terms and Conditions
  • Privacy Policy
  • Notice of Privacy Practices
  • Notice of Nondiscrimination
  • Manage Cookies

Advertising

Mayo Clinic is a nonprofit organization and proceeds from Web advertising help support our mission. Mayo Clinic does not endorse any of the third party products and services advertised.

  • Advertising and sponsorship policy
  • Advertising and sponsorship opportunities

Reprint Permissions

A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.org," "Mayo Clinic Healthy Living," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research.

© 1998-2022 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved.