What is a mammogram?

Mammography is a test that uses X-rays to create images of the breast. These images are called mammograms.

A radiologist trained to read mammograms studies the images and looks for signs of breast cancer.

Digital mammography

In the past, mammogram images were stored on film (film mammography). Now, mammogram images are usually stored on a computer (digital mammography). This makes it easy to share digital images with another radiologist for review.

Since digital images are viewed on a computer, they can be lightened or darkened, and certain sections can be enlarged and looked at more closely.

How is mammography used?

Screening

Breast cancer screening tools are used to find breast cancer in a woman with no warning signs or symptoms.

Overall, mammography is the most effective screening tool used to find breast cancer in most women. It can find cancers at an early stage, when the chances of survival are highest.

Learn about mammography recommendations for women at average risk of breast cancer.

Learn about mammography recommendations for women at higher than average risk of breast cancer.  

Follow-up

Mammography can be used as a follow-up test when something abnormal is found on a screening mammogram or a clinical breast exam.

A mammogram used as a follow-up test (instead of screening) is called a “diagnostic mammogram.” Although it’s called a “diagnostic mammogram,” it can’t diagnose breast cancer. It can show whether the abnormal findings look like breast cancer though.

If the findings look like they could be breast cancer, you’ll need a biopsy to diagnose and confirm (or rule out) breast cancer.

Whether you’re getting a screening mammogram or a diagnostic mammogram, the basic procedure is the same. However, with a diagnostic mammogram, more views will likely be taken. 

Getting a mammogram

If you’re getting a mammogram for the first time, you may have questions about what to expect (before and after).

Learn about getting a mammogram, including information for women who have breast implants, are pregnant or breastfeeding, or who have a physical disability.

Findings on a mammogram

Like other X-ray images, mammograms appear in shades of black, gray and white, depending on the density of the tissue. Dense breast tissue looks different from fatty breast tissue on a mammogram.

Learn more about breast density on a mammogram.

A mammogram may show:

• No signs of breast cancer
• A benign condition
• An abnormal finding that needs follow-up tests to rule out cancer

Learn more about findings on a mammogram and when to expect your mammography results.

Follow-up after an abnormal mammogram

If your mammogram shows something abnormal, you’ll need follow-up tests to check whether or not the finding is breast cancer.

Learn about follow-up after an abnormal mammogram.

Accuracy of mammograms

Although mammography is the most effective screening tool used today to find breast cancer in most women, it’s not perfect.

Learn about the accuracy of mammograms.

	For a summary of research studies on mammography in women ages 40-49, visit the Breast Cancer Research Studies section.
	For a summary of research studies on mammography in women ages 50-69, visit the Breast Cancer Research Studies section.
	For a summary of research studies on 3D mammography for breast cancer screening, visit the Breast Cancer Research Studies section.

Weighing the risks and benefits of mammography

Most major health organizations agree mammography lowers a woman’s risk of dying from breast cancer [2-4].

However, there’s ongoing debate about how much benefit there is from mammography (especially in younger women) and whether this benefit outweighs the risks.

There’s also debate about when to begin mammography and how often to have it.  

Learn more about the benefits and risks of mammography.

Women Should Have Access to and Coverage for Mammography

Susan G. Komen® believes all women should have access to regular screening mammograms when they and their health care providers decide it is best based on their personal risk of breast cancer. In addition, screening should be covered by insurance companies, government programs and other third-party payers.

Radiation exposure during a mammogram

You’re exposed to a small amount of radiation during a mammogram. While this radiation exposure might increase the risk of breast cancer over time, this increase in risk is very small [5-7].

Studies show the benefits of mammography outweigh the small risks from radiation exposure, especially for women ages 50 and older [5-6,8].

Low-cost or free mammograms

Medicare, Medicaid and most insurance companies cover the cost of mammograms.

Since September 2010, the Affordable Care Act has required all new health insurance plans to cover screening mammograms every 1-2 years for women ages 40 and older, with no out-of-pocket costs (co-payments or co-insurance) [16].

If you don’t have insurance or your insurance doesn’t cover mammograms, the resources below may help you find a low-cost or free mammogram (or help with the cost).

• The Komen Breast Care Helpline can help you find low-cost breast cancer screening in your area. Call the helpline at 1-877 GO KOMEN (1-877-465-6636) Monday through Friday from 9:00 a.m. to 10:00 p.m. ET.
• The National Breast and Cervical Cancer Early Detection Program provides access to breast cancer screening to low-income, uninsured and underinsured women ages 40-64. It also provides access to diagnostic testing if results are abnormal, and referrals to treatment if breast cancer is diagnosed.