A mammogram is an x-ray picture of the breasts. It is used to find tumors and to help tell the difference between noncancerous (benign) and cancerous (malignant) disease. One breast at a time is rested on a flat surface that contains the x-ray plate. A device called a compressor is pressed firmly against the breast to help flatten out the breast tissue. Each breast is compressed horizontally, then obliquely and an x-ray is taken of each position.
Review Date 4/30/2022
Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.