A mammogram is an X-ray of the breast. It’s a screening tool used to detect and diagnose breast cancer. Together with regular clinical exams and monthly breast self-examinations, mammograms are a key element in the early diagnosis of breast cancer.

Most experts recommend that women who are 40 years old and older should have mammography every one to two years. The American Cancer Society recommends regular screening beginning at age 45. If you have a personal or family history of breast cancer, your doctor may recommend that you start screenings earlier, have them more often, or use additional diagnostic tools.