A mammogram is a two-dimensional, black-and-white X-ray of the breast that is done to screen for breast cancer and to investigate lumps that can be felt during a breast exam. A mammogram can also detect tumors or abnormal areas that are too small to be felt with the hands.

Mammograms done on a regular schedule help reduce a woman's risk of death from breast cancer. Yearly mammograms often are recommended for women older than age 40 and for women who have a strong family history of breast cancer, even if they are younger than 40.