Preparing for a Mammogram

What Is a Mammogram?

A mammogram is an X-ray of the breast recorded on X-ray film or digitally to a computer. These images are then examined by a doctor called a radiologist, who looks for changes in breast tissue and tumors that are often not felt. Mammograms and breast self-exams are important tools for assessing breast changes and diagnosing breast cancer in its earliest and most curable stage.


Screening mammograms look for signs of cancer before a person has symptoms and are performed with a regularity that is determined between you and doctor. The technologist usually takes two views per breast, one from the top and another from the side.

Diagnostic mammograms are used to diagnose breast disease in people with unusual symptoms, such as changes in breast size/shape, nipple discharge or lumps felt during self-exams, or in follow-up appointments to screenings that present abnormal results. The technologist usually takes several views or angles of each breast.

3D mammography, also known as tomosynthesis, provides a more detailed view of the breast in comparison to X-ray mammography. This 3D machine moves over the compressed breast, taking an X-ray that is transferred into a 3-dimensional picture. Tomosynthesis exposes women to a slightly higher dose of radiation than traditional mammography, but it also provides a more detailed image and therefore reduces the callback rate for additional testing. Most often, it is performed in addition to a regular mammogram.

How Is It Performed and How Does It Feel?

At the time of your appointment you will be given a robe to wear so you can remove your clothing from the waist up. Your technician will position your breast between two plates attached to the machine which will compress the breast. You will feel pressure for a few seconds but the compression is important for a quality image of the breast tissue. For a screening mammogram, plan for approximately 30 minutes, and up to 60 minutes for a diagnostic appointment.

Please let your technologist know if you feel very uncomfortable or have pain. Also discuss any breast symptoms and previous breast surgeries (if any) before the compression begins. This discussion should include disclosure of biopsies, lumpectomies, mastectomies and implants. Scheduling your appointment when your breasts are not tender or swollen allows for the most comfortable mammogram possible. Refrain from a mammogram the week before your period when breasts are most sensitive.

Preparing for Your Mammogram

  • Do not use deodorant, lotions or powders on breasts or underarms the day of the mammogram.
  • Bring or send previous mammograms for the technician and radiologist to use in analysis.
  • Please note that being called back for additional testing is quite common and does not mean you have cancer.

Additional Procedures, If Necessary

Some additional procedures may be performed to diagnose or analyze images.

  • Breast ultrasounds are imaging tests using sound waves to create an alternative picture of the breast and allow for further examination by a radiologist. These tests are sometimes used in combination with a mammogram.
  • A biopsy is sample tissue or fluid removed from the breast to help diagnose whether cancer is present. Your doctor will refer you to a specialist for this procedure.