Mammogram

A mammogram is an X-ray of your breast tissue. Healthcare providers use mammograms to look for early signs of breast cancer. Women at average risk for breast cancer should start getting mammograms at age 40.

During a mammogram, a machine presses your breasts between two plates for several seconds. An X-ray takes pictures of your breast tissue. A radiologist looks at these images on a computer screen to check for signs of cancer.

Mammograms can detect abnormal areas in your breast, but they can't diagnose breast cancer. If a mammogram finds something unusual, you’ll need imaging tests that check the area more closely.

Why it’s done

Mammograms look for changes in your breast tissue that could be a sign of breast cancer. It can be used for screening or to help make a diagnosis.

• Screening mammograms are for when you don’t have any symptoms. Routine mammograms are key to catching breast cancer early, when it’s easier to treat.
• Diagnostic mammograms are for when you have breast symptoms, like a new lump or nipple discharge. You may also need one if a screening mammogram finds an unusual area that needs more testing.

What are the different types of mammograms?

A traditional mammogram creates 2D images. It involves taking pictures of each breast at two different angles — typically from top to bottom and side to side.

A 3D mammogram (breast tomosynthesis) is a newer type of mammogram. During this test, the machine moves in an arc over your breast and takes several X-rays. A computer combines these images into “slices.” This lets your provider view your breast tissue in 3D.

At what age do you get a mammogram?

Most healthcare providers recommend getting a mammogram every year beginning at age 40. You should keep having one as long as you’re in good health. Some medical groups have different recommendations. Talk with your healthcare provider about what is right for you.

If you have a higher risk of developing breast cancer or a family history of breast cancer, you may need to have screening mammograms before age 40. Your provider may also recommend additional tests like a breast ultrasound or breast MRI.

Talk to your healthcare provider about how often you should have a mammogram based on your medical history, previous mammograms and other factors.

How does a mammogram work?

A mammogram uses an X-ray machine that’s made just for breast imaging.

During a mammogram, you place your breast on a plate attached to the X-ray machine. A technologist gently squeezes your breast with a plate called a paddle. This compression is an important part of the test because it helps create clear images. The machine sends X-rays through your breast tissue and creates an image.

How to prepare for a mammogram

Here are a few things to know before your mammogram:

• If you’re pregnant or think you may be pregnant, tell your healthcare provider.
• If you’re breastfeeding, pump or nurse right before your mammogram to empty your breasts. This can make the images clearer and the exam more comfortable.
• If you still get a period, try not to schedule your mammogram the week before you get your period or during your period. Your breasts may be tender during this time, which can make the test uncomfortable.
• Tell the scheduler if you have breast implants or have recently gotten a vaccine.

On the day of your mammogram, follow these guidelines:

• Follow your usual routine — eat, drink and take your normal medications.
• Don’t wear deodorant, perfume, lotion or body powder. These products can affect the X-ray images.
• You’ll need to undress from your waist up. You’ll have a medical gown or drape to wear.

What to expect during a mammogram

A mammogram involves the following steps:

1. You’ll remove all clothing and jewelry above your waist. A provider will give you a hospital gown that opens in the front.
2. You’ll stand in front of the mammography machine, and the technologist will ask you to remove one breast at a time from your gown. You’ll place your breast on a breast support plate.
3. The technologist will lower a plastic paddle to compress your breast against the support plate. You may feel some discomfort during this time. If you’re uncomfortable, tell the technologist. They may be able to adjust the plates.
4. The X-ray machine will take images of your breast while it’s compressed.
5. If you have two breasts, you’ll repeat this process for your other breast.
6. After taking the images, the technologist may check them to make sure they’re clear.

Screening mammograms usually take about 15 to 20 minutes. Diagnostic mammograms may take longer because your provider may need more images.

Do they hurt?

Having a mammogram can feel uncomfortable due to the pressure on your breast tissue from the compression. The good news is that the discomfort doesn’t last long and the test is short. If you feel intense pain, tell the technologist right away.

What to expect after a mammogram

A radiologist reviews your images and looks for signs of cancer. They put their findings into a report and share them with your healthcare provider. You usually receive a phone call or a letter in the mail explaining your results. They’re typically in your electronic medical records online, too.

Are mammograms safe?

Mammograms are safe. Mammograms expose your breasts to small amounts of radiation, but the benefits of mammography outweigh the risks.

Mammograms can help find breast cancer early. But they’re not perfect. They may miss some cancers, and they can sometimes find areas that need more testing but turn out not to be cancer.

How long does it take to get mammogram results?

You usually get your mammogram results within a week, although this can vary. Often, radiologists compare your most recent mammogram to your last mammogram.

Contact your provider or the place you got your mammogram if you don’t receive your results within a month.

What do mammogram results mean?

Your results will either be normal or abnormal. You’ll get a letter that explains your results in words you can understand.

• Normal: A normal mammogram means the radiologist didn’t see any concerning changes or abnormal areas in your breast images.
• Abnormal: The radiologist saw a concerning area that they want to take a better look at. You’ll likely need another mammogram or other test like a breast ultrasound or a breast MRI. Your healthcare provider will go over the next steps with you if you receive an abnormal result.

Even with a normal mammogram result, it’s important to continue getting mammograms as often as your healthcare provider recommends. Screening mammograms are most helpful when radiologists can compare mammograms over time.

Your report will include information about your breast density. Breast density describes how much fibroglandular tissue you have compared with fatty tissue. By law, providers must include this information in your report. Breast density can affect how easily a mammogram can find cancer.

It will also include a Breast Imaging Reporting and Data System (BI-RADS) category. This is a standard system radiologists use to describe mammogram results. The categories are numbered 0 through 6.

If you have questions about your results or breast density, ask your healthcare provider.

How accurate is mammography?

Mammograms can find about 85% of breast cancers. They’re the gold standard for detecting breast cancer. They can find breast changes before you can see or feel them. Finding breast changes early means treatment can begin sooner if cancer is present.

Contact a healthcare provider right away if you notice a new lump, nipple discharge, skin changes or any other new breast symptoms.