A mammogram is an x-ray examination of the breast. It is used to detect breast disease in women who have breast problems such as a lump, pain, or nipple discharge, as well as for women who need routine screening.

In the past 15 years, technical advancements have greatly improved both the technique and results of mammography. Today, equipment specialized for breast x-raying makes high quality images with a very low radiation dose.

Types of mammograms include:

  • Screening mammogram — A breast x-ray used to detect breast changes in women who have no signs of breast cancer. It usually involves two x-rays of each breast. Using a mammogram, it’s possible to detect a tumor that cannot be felt.
  • Diagnostic mammogram — A breast x-ray used to diagnose unusual breast changes, such as a lump, pain, thickening, nipple discharge, or change in breast size or shape. This is also used when it is difficult to obtain a clear screening mammogram in special cases, such as with breast implants.
  • Digital mammogram — A technique for recording x-ray images in computer code instead of on x-ray film. A computer monitor can then display images where they can be enhanced before being printed on film. Because a radiologist can adjust the images, subtle differences between tissues may be noted.

Mammography cannot prove that an abnormal area is cancer. If it does raise a valid concern, tissue will be removed for a biopsy. Tissue may be removed by needle or open surgical biopsy and examined under a microscope to determine if it is cancer.

What are the guidelines for having mammograms?

National Cancer Institute Guideline for Screening Mammography

Women in their 40s and older should have a screening mammogram on a regular basis, every one to two years.

American Cancer Society Guideline for Screening Mammography

Women 40 years of age and older should have a screening mammogram every year.