Frequently Asked Questions Expand All
Fibrous tissue and fat give breasts their shape. Breasts are called dense when a mammogram shows more fibrous tissue and less fat.
Dense breasts don’t feel any different than breasts with more fatty tissue. This means you can’t tell if you have dense breasts on your own or with a clinical breast exam. Mammograms can show if breasts are dense.
Dense breasts are normal and common, especially among younger women. Almost half of women age 40 and older who get mammograms are found to have dense breasts.
Radiologists sort breast density into four categories:
Almost entirely fat
Some dense areas, but mostly fat
Some fatty areas, but mostly dense
Breasts in category 3 or 4 are considered dense. The radiologist reading the mammogram chooses the category based on their expert opinion.
Dense breast tissue and cancerous lumps both look white on a mammogram. This can make it harder for the radiologist to read the mammogram and identify cancers. See Mammography and Other Screening Tests for Breast Problems for more information on mammography.
Women with dense breasts have a modestly higher risk of breast cancer than women without dense breasts. The risk increases as breast density increases. Dense breasts do not increase the risk of dying from breast cancer.
The American College of Obstetricians and Gynecologists (ACOG) does not recommend extra screenings for women with dense breasts who do not have other risk factors. This is because research does not show that extra or different screening methods reduce breast cancer deaths in these women.
Some states require health care professionals to discuss extra screenings with women who have dense breasts. Talk with your obstetrician–gynecologist (ob-gyn) about your risk for breast cancer and your screening needs. Extra screenings may be needed for women at high risk of breast cancer.
Body Mass Index (BMI): A number calculated from height and weight. BMI is used to determine whether a person is underweight, normal weight, overweight, or obese.
Hormone Therapy: Treatment in which estrogen and often progestin are taken to help relieve symptoms that may happen around the time of menopause.
Mammogram: An X-ray image used to show breast cancer or other breast problems.
Mammography: X-rays of the breast that are used to find breast cancer or other breast problems.
Obstetrician–Gynecologist (Ob-Gyn): A doctor with special training and education in women’s health.
Radiologists: Physicians who specialize in interpreting images taken with various medical imaging techniques.
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Published: October 2020
Last reviewed: October 2020
Copyright 2021 by the American College of Obstetricians and Gynecologists. All rights reserved. Read copyright and permissions information.
This information is designed as an educational aid for the public. It offers current information and opinions related to women's health. It is not intended as a statement of the standard of care. It does not explain all of the proper treatments or methods of care. It is not a substitute for the advice of a physician. Read ACOG’s complete disclaimer.
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