Dense Breast Notification: What to Ask

This page is for anyone who got a letter saying their breasts are dense. It explains what the letter means and what to ask your doctor.

A dense breast notification means your mammogram showed a lot of glandular and fibrous tissue, and not much fat. It is common, not a cancer diagnosis, but it changes two things worth understanding: how well a standard mammogram can see through your tissue, and your personal risk of breast cancer.

This page is educational. It is not medical advice and does not suggest a test or treatment.

Under an FDA rule issued in 2023 and effective September 2024, mammography facilities in the United States must give you a written summary that includes your breast density. Density is graded into four categories. They range from almost entirely fatty to extremely dense. The two densest categories both count as "dense" on your letter. FDA says about half of women over 40 in the U.S. have dense breast tissue. So getting this letter does not mean anything went wrong with your mammogram, or your health.

Only a radiologist reading your mammogram can tell whether your breasts are dense. NCI says dense tissue cannot be felt by you or your doctor.

Your report uses one of four phrases, from least to most dense:

• Almost entirely fatty. Not labeled dense.
• Scattered areas of fibroglandular density. Not labeled dense.
• Heterogeneously dense. This may hide small masses. It counts as dense.
• Extremely dense. This lowers how well mammography works. It counts as dense.

If your letter uses one of the last two phrases, that is the "dense" result this page is about.

Dense tissue matters for two separate reasons. First, it is itself a risk factor for breast cancer. NCI says women with dense breasts have a higher risk of breast cancer than women with fatty breasts. Second, dense tissue makes mammograms harder to read. Both tumors and dense glandular tissue show up white on a mammogram. NCI says mammography is more likely to miss cancer in women with dense breasts.

A dense breast notification is not a diagnosis. It does not by itself mean you need a different test. NCI says there is not yet enough evidence to recommend for or against extra imaging, like ultrasound or MRI, for every woman with dense breasts. That gap is exactly why this is a conversation to have with your own doctor, not a box to check on your own.

Before your visit, you might plan to ask:

• What density category was reported for me specifically, not just "dense" in general?
• Should my overall breast cancer risk be calculated with a formal risk tool? Density is only one factor. Age, family history, and prior biopsies matter too.
• Does extra screening, such as ultrasound or MRI, make sense for my personal risk level?
• How should my future mammogram reminders be scheduled? Density can change over time, and NCI notes it tends to be lower with increasing age.

• How does my dense breast notification fit with my health history and any symptoms I have?
• After my dense breast notification, what should happen now, what can wait, and what should make me call sooner?
• Is there a written plan, handout, or referral that would make this easier to follow?
• Who do I contact after hours about my dense breast notification, and what should I have ready?

Dense breast tissue does not replace paying attention to your own body. Report a new lump, nipple change, skin change, or pain that persists in one spot to your doctor, even if your last mammogram was normal and even if you are not due for another one yet. Density affects how well a mammogram can see, not how real a new symptom is.

This page connects to how mammograms work, breast cancer risk assessment, and what to do after any abnormal screening result. Related pages: What Does a Mammogram Callback Mean?, What to Ask After an Abnormal Cancer Screening Test, Colonoscopy Prep Questions for Cancer Screening.

• U.S. Food and Drug Administration — Understanding Breast Density.
• National Cancer Institute — Dense Breasts: Answers to Commonly Asked Questions.