Breast Density: Who Knows? We Do! (And So Should You)

Breast Density: Who Knows? We Do! (And So Should You)

As doctors, medical terminology is an integral part of our workday, but we realize not everyone has familiarity with those crazy Latin roots or the phrases that we use and re-use! However, there are some medical words and phrases that it would behoove you to know.


“Breast density” is one such term. Every mammography report includes a statement about it, and all women should have an understanding of what it means. However, according to a new study, nearly half of all women who should be getting mammograms had never heard of breast density. Yikes – there is room for more education here!.


Breast density is not something that can be discovered by a physical breast exam, either your own self-exam or your doctor’s clinical breast exam. Mammography reveals the internal structures of the breast with an image of varying shades of black, gray and white depending on the relative amounts of fat and glandular tissue. Breast density is described on a scale from fatty breasts to dense breasts. A fatty breast is one where most of the tissue has been replaced by fat with the image mostly dark gray. A dense breast on the other hand has mostly glandular tissue and will appear as mostly white. Many breasts fall somewhere in the middle.


Cancers often appear as white on a mammogram, whether a mass or tiny microcalcifications. One of the important reasons you should know about breast density is dense breasts make it harder to find some breast cancers on a mammogram. Simply put, it is harder to find a small white object (a potential cancer) on a background of white seen on a dense mammogram.


The other important reason you should know about your breast density is the small but real increase in the risk of breast cancer in those women with dense breasts. This is on the order of a 3-4% increase. Here’s what YOU can do:

  • Doctors are only required to disclose if you have dense tissue in a handful of states. If you are not in one of those states you can still find out your breast density from the report or discussion with your doctor and/or radiologist.
  • If you have dense breasts, knowing your other risk factors is important. If this is your only other risk factor for breast cancer (other than being female!), routine annual screening with mammography may be all you need. Getting that mammogram every year is important to assess for changes!
  • If you have other risk factors in addition to dense breasts, supplemental imaging may be a good idea. This can include breast MRI for those with high risk (for example having a mother or sister with premenopausal breast or ovarian cancer) or breast ultrasound if intermediate in risk.


As the saying goes, knowledge is power. And knowing if you have dense breasts (and what to do about it) can save your life – that’s really powerful!





Image credit: Question Mark by Leo Reynolds via Flickr Copyright Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Generic (CC BY-NC-SA 2.0)

Originally published 4/3/15 on