Skip to main navigation
Skip to main content

This content does not have an English version.

This content does not have an Arabic version.

Request an Appointment
Find a Doctor
Find a Job
Give Now

Log in to Patient Account
English

Twitter
Facebook
Google
YouTube
Pinterest

English

All Mayo Clinic Topics

Patient Care & Health Info
Quality CareFind out why Mayo Clinic is the right place for your health care. Make an appointment.
Departments & Centers
Meet the StaffFind a directory of doctors and departments at all Mayo Clinic campuses. Visit now.
Research
Research and Clinical TrialsSee how Mayo Clinic research and clinical trials advance the science of medicine and improve patient care. Explore now.
Education
Visit Our SchoolsEducators at Mayo Clinic train tomorrow’s leaders to deliver compassionate, high-value, safe patient care. Choose a degree.
For Medical Professionals
Professional ServicesExplore Mayo Clinic’s many resources and see jobs available for medical professionals. Get updates.
Products & Services
Giving to Mayo Clinic
Philanthropy at Mayo ClinicYour support accelerates powerful innovations in patient care, research and education. Give today.

About This Site

Products and services

Free E-newsletter

Subscribe to Housecall

Our general interest e-newsletter keeps you up to date on a wide variety of health topics.

Corrections policy

One of this site's policies is to correct original content that may be confusing, misleading or inaccurate. By Mayo Clinic Staff

Our mission is to provide accurate and useful health information. If we determine that our content contains confusing, misleading or inaccurate information, we will revise the content. This policy applies to all original content.

There are no corrected items.

Dec. 05, 2012

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

Advertising & Sponsorship

Policy
Opportunities
Ad Choices

Mayo Clinic Footer

Request Appointment
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.