What is breast density and why does it (maybe matter)? We know that it is more difficult to read mammograms of dense breasts (which are normal for pre-menopausal women). The simile is that "it is like looking for a polar bear in a snow storm." There are also suggestions that dense breasts may carry a higher risk for breast cancer. This is an excellent primer from Komen about this issue. I give you the beginning and then a link to read more:
The ABCs of Breast Density (August 2011)
You may have heard health reports about the importance of breast density on a mammogram (also called mammographic density), which has emerged as a strong risk factor for breast cancer in women. But what, exactly, is breast density? What is its role in breast cancer? How do you know if you have dense breasts?
And, if you do have dense breasts, is there anything you can do to lower your breast cancer risk?
A woman's breasts are made up mostly of fat and breast tissue. Breast tissue is the network of lobules (sacs that produce milk) and ducts (canals that carry milk from the lobules to the nipple openings during breastfeeding). Connective tissue helps hold everything in place.
What is breast density?
Breast density is a way to describe the composition of a woman's breasts. This measure compares the area of breast and connective tissue seen on a mammogram to the area of fat. Breast and connective tissue are denser than fat and this difference shows up on a mammogram.
High breast density means there is a greater amount of breast and connective tissue compared to fat. Low breast density means there is a greater amount of fat compared to breast and connective tissue.