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National Cancer Institute

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Learn About Mammograms

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Posted: 10/01/2010

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Screening and Testing to Detect Cancer: Breast Cancer
Screening methods are discussed, including clinical breast exam, mammography, and other imaging techniques.

When breast cancer starts, it is too small to feel and does not cause signs and symptoms. Mammograms help doctors look for early signs of breast cancer. If breast cancer is found early, it may be possible to treat it before it spreads.

In 2008, more than 75% of women over 40 reported having a mammogram in the past 2 years. However, women may have questions about when to start getting regular mammograms and about the benefits and potential harms. Physicians and other health care providers may also want to better understand the scientific evidence about the use of screening mammograms.

On this page

For Women
For Health Professionals

For Women

Women age 40 and older should have mammograms every 1 to 2 years. Women who are at higher than average risk of developing breast cancer should talk with their health care providers about whether to have mammograms before age 40 and how often to have them.

Understanding Mammograms and Your Risk of Breast Cancer helps you find answers to some basic questions that you may have on this topic.
NCI Fact Sheet on Mammograms explains the difference between screening mammograms and diagnostic mammograms and discusses risk factors in greater detail.
Understanding Breast Changes: A Health Guide for Women helps women understand next steps after an abnormal mammogram result.

Need to find a place where you can get a mammogram?
Use the Mammography Facility Database from the Food and Drug Administration (FDA) to find certified facilities that provide mammograms in a location near where you live or work.

What if you don’t have insurance?
The National Breast and Cervical Cancer Early Detection Program Web site has a list of contacts in the U.S. states, territories, and Native American tribal areas. Contact them to see if you are eligible for assistance.

For Health Professionals

Research shows that screening mammography helps reduce the number of deaths from breast cancer among women ages 40 to 74. However, in addition to this benefit, mammography has some limitations and potential harms.

Screening Mammography: Help With Explaining Benefits and Potential Harms is designed to help you talk to your patients about issues such as false-negative and false-positive results and overdiagnosis.
Key Facts About a Woman’s Risk of Developing and Dying From Breast Cancer presents information in tables to help you look up an average American woman’s risk of developing and dying from breast cancer at different ages.

Looking for a tool to help you discuss breast cancer risk with your patients?
NCI’s Breast Cancer Risk Assessment Tool helps you compute a woman’s risk of developing breast cancer over the next 5 years.

To talk with an NCI information specialist in English or Spanish, call the National Cancer Institute’s Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237) or chat with us at https://livehelp.cancer.gov/, Monday through Friday, 8:00 a.m. to 8:00 p.m., Eastern Time. Our service is free and confidential.

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