Approved by the Cancer.Net Editorial Board, 06/2019

Mammography is an x-ray that checks for breast cancer in women. The images that it produces are called mammograms. These images may show small tumors that cannot be felt. Mammograms may also show other irregularities in the breast.

What are the main types of mammograms?

Screening mammogram. This test looks for breast cancer in women with no symptoms. The goal is to catch the disease early, when it may be more treatable.

Organizations develop screening guidelines based on the benefits and risks of mammography. These recommendations may differ slightly. Learn about current breast cancer screening guidelines and how to make sense of screening recommendations.

Diagnostic mammogram. You may receive this test to answer a specific question or learn more about a specific symptom. It may be recommended for the following reasons:

  • A screening mammogram shows a suspicious area

  • You feel a lump in the breast

  • You have other unusual symptoms

A diagnostic mammogram usually takes more pictures of the breast than a screening mammogram.

Who does my mammogram?

This test is performed by a mammogram technologist known as a mammographer. A mammographer is specially trained to take x-ray images of the breasts.

A doctor who specializes in reading medical imaging tests reviews the mammogram. This type of doctor is called a radiologist.

How should I prepare for a mammogram?

Topics to discuss with your health care team. Discuss any breast symptoms you are experiencing. Mention if you are pregnant or breastfeeding. In both cases, your doctor will probably recommend postponing this test.

Scheduling and other time-related preparations. Consider scheduling the test within the 2 weeks after your menstrual period ends. Women's breasts are least tender during this time.

Other factors that may reduce breast sensitivity:

  • Avoiding caffeine for a week before the test

  • Taking an over-the-counter pain medication on the test day

Financial preparation. Before your appointment, check with your insurance provider. Ask whether insurance covers the mammogram costs. And ask whether you may need to pay for part of it.

The Affordable Care Act requires that private insurance companies pay the full cost of mammography screening. Starting at 40, women may receive screening every 1 to 2 years. Medicare covers yearly mammography screening, starting at age 40.

Diagnostic mammography is usually covered by your insurance provider. But you should confirm this to avoid unexpected costs.

Physical preparation. Before the mammogram, do not use these products:

  • Deodorant

  • Antiperspirant

  • Powder

  • Lotion

  • Perfume

They leave residue on the skin that could create spots on the x-ray.

Take off jewelry that will interfere with the x-ray. You will be asked to remove your clothes above the waist and wear a hospital gown that opens in the front.

Communication. Tell the technologist if you have:

  • Breast implants

  • Previous breast surgery (You may be asked to point out any scars.)

  • Any area of concern in your breast

This helps the technologist better perform the mammogram. And it helps the radiologist read your mammogram more accurately.

If you had previous breast surgery, the technologist may tape small markers to your skin at the scar site. This will show the radiologist where you have the highest risk of recurrence.

If you have had a mammogram before, bring copies of the images to share with the radiologist.

What will happen during the test?

The actual mammogram takes 10 to 15 minutes. But the whole process takes up to an hour. This includes changing clothes, having the examination, and making sure the images are clear.

The technologist may ask you to relax and take a deep breath as the procedure begins.

You will stand in front of the mammography machine. Then, the technologist will:

  • Place 1 of your breasts between 2 plates

  • Press the plates together to flatten your breast

  • Take an x-ray, which lasts a few seconds

Flattening your breast spreads out the tissue. This makes it easier to find small abnormalities. It also prevents motion that would blur the image.

For a screening mammogram, the technologist will take images of each breast. More images may be taken for a diagnostic mammogram. You may change positions slightly for each image. Then, the technologist makes sure the pictures are clear and readable.

After review, the technologist may need to take more images.

After the test

You can return to your usual activities right after your mammogram. You will receive the results within 30 days.

Advances in mammography

Most breast imaging centers have switched from using film screens to digital mammography. The digital images are clearer and easier to read.

Digital mammography

Digital mammograms record the images on a computer, rather than on film. Digital records are easier to store and share with other health care professionals. The image contrast is also sharper, which can make it easier to find small changes.

3-D breast imaging

Another advance is 3-dimensional (3-D) breast imaging. It is also called breast tomosynthesis.

For this exam, the breast is positioned and flattened the same way it is for a digital mammogram. But a tomosynthesis takes a few seconds longer than a digital mammogram. This is because an x-ray tube moves in an arc and takes pictures of the breast from many angles. The information is processed by a computer, which creates images that show multiple thin sections of the breast. A radiologist analyzes the results.

Some studies show that 3-D imaging results in fewer follow-up exams. Many breast imaging centers do this test but it is not yet widely available.

Each type of mammography has benefits and risks. Ask your health care team which type is right for you.

Questions to ask your health care team

Before having a mammogram, consider asking your health care team these questions:

  • Who will do the mammogram?

  • What experience does the center have in doing mammography?

  • What are the possible risks and benefits of a mammogram?

  • How accurate is mammography at finding cancer?

  • When will I learn the results? How will I be told?

  • Who will explain the results to me?

  • What other tests will I need if the mammogram is unclear or shows signs of cancer?

Related Resources

Breast MRI

Guide to Breast Cancer

Cancer Screening

More Information

MedlinePlus: Mammography

National Cancer Institute: Mammograms

RadiologyInfo: Mammography