What is dense breast tissue?

What is dense breast tissue?

Dense breast tissue refers to the amount of glandular tissue and connective tissue you have in your breast compared to fatty tissue. When there is more glandular and connective tissue than fat, the breast is considered dense. Having dense breast tissue is very common.

What are the parts of the breast?

The breasts are made of several types of tissue, including glandular, fatty and fibrous connective tissue. The glandular tissue is made up of lobules (responsible for making milk) and ducts (tree-like system of tubes that carries milk from the lobules to the nipple). Glandular and duct tissue is white on a mammogram.

The fatty tissue, also called adipose tissue, stretches up to the collarbone and down to the ribcage. Fatty tissue is dark on a mammogram.

Are there different categories of dense tissue?

Breast density is divided into four categories, ranging from having very little dense tissue to extremely dense tissue. The four categories are:

  • Type 1: Majority fatty tissue
  • Type 2: Some scattered dense tissue
  • Type 3: More dense tissue than fatty tissue
  • Type 4: Extremely dense tissue with very little fatty tissue

Most women are either type 2 or 3. This means they have some combination of dense and fatty tissue.