A mammogram is an x-ray picture of the breasts. It is used to find breast tumors and cancer.

Alternative Names

Mammography; Breast cancer - mammography; Breast cancer - screening mammography; Breast lump - mammogram; Breast tomosynthesis

How the Test is Performed

You will be asked to undress from the waist up. You will be given a gown to wear. Depending on the type of equipment used, you will sit or stand.

One breast at a time is rested on a flat surface that contains the x-ray plate. A device called a compressor will be pressed firmly against the breast. This helps flatten the breast tissue.

The x-ray pictures are taken from several angles. You may be asked to hold your breath as each picture is taken.

You may be asked to come back at a later date for more mammogram images. This does not always mean you have breast cancer. Your health care provider may simply need to recheck an area that could not be clearly seen on the first test.


Traditional mammography uses film, similar to routine x-rays.

Digital mammography is a newer technique:

Three-dimensional (3D) mammography is a type of digital mammography. Researchers do not yet know whether 3D mammography is more or less accurate than standard mammogram.

How to Prepare for the Test

DO NOT use deodorant, perfume, powders, or ointments under your arms or on your breasts on the day of the mammogram. These substances may hide the images. Remove all jewelry from your neck and chest area.

Tell your provider and the x-ray technologist if you are pregnant or breastfeeding, or if you've had a breast biopsy.

How the Test will Feel

The compressor surfaces may feel cold. When the breast is pressed down, you may have some pain. This needs to be done to get good quality images.

Why the Test is Performed

When and how often to have a screening mammogram is a choice you must make. Different expert groups do not fully agree on the best timing for this test.

Before having a mammogram, talk to your provider about the pros and cons of having the test. Ask about:

Mammography is performed to screen women to detect early breast cancer when it is more likely to be cured. Mammography is generally recommended for:

Mammography is also used to:

Normal Results

Breast tissue that shows no signs of a mass or calcifications is considered normal.

What Abnormal Results Mean

Most abnormal findings on a screening mammogram turn out to be benign (not cancer) or nothing to worry about. New findings or changes must be further evaluated.

A radiology doctor (radiologist) may see the following types of findings on a mammogram:

At times, the following tests are also needed to further examine mammogram findings:

Comparing your current mammogram to your past mammograms helps the radiologist tell whether you had an abnormal finding in the past and whether it has changed.

When mammogram or ultrasound results look suspicious, a biopsy is done to test the tissue and see if it is cancerous. Types of biopsies include:


The level of radiation is low and any risk from mammography is very low. If you are pregnant and need to have an abnormality checked, your belly area will be covered and protected by a lead apron.

Routine screening mammography is not done during pregnancy or while breastfeeding.


American Cancer Society. American Cancer Society Recommendations for Early Breast Cancer Detection in Women Without Breast Symptoms. Updated October 20, 2015. Accessed March 17, 2016.

American College of Obstetricians and Gynecologists (ACOG). ACOG statement on breast cancer screening guidelines. Updated 2016. Accessed March 17, 2016.

National Cancer Institute: PDQ Breast Cancer Screening. Bethesda, MD: National Cancer Institute. Updated March 4, 2016. Accessed March 9, 2016.

U.S. Preventive Services Task Force. Final Update Summary: Breast Cancer: Screening. Updated February 2016. Accessed March 17, 2016.

Review Date: 2/11/2016
Reviewed By: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
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