What Breast Density Means
Glandular tissue versus fatty tissue, and why it matters on a mammogram.
The breast is made up of glandular and connective tissue on one hand and fatty tissue on the other. The ratio between these parts is what we call breast density. It says nothing about the shape or firmness of your breast, but rather about the internal structure, which only becomes visible on a mammogram.
Radiologists classify density into four levels under the ACR system, from a to d. ACR a is an almost entirely fatty breast, while ACR d is a very dense breast made up of mostly glandular and connective tissue. Younger women tend to have denser tissue, and density often decreases with age.
Why this matters is covered in the next article. [internal link: What dense tissue means for your risk]
This content is for information only and does not replace medical advice.