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.

Diagnosis and Tests

How is dense breast tissue diagnosed?

Dense breast tissue is diagnosed during a mammogram. A radiologist is a physician who reads X-rays, including mammograms. She/he will describe your breast density based on how your tissue looks on your mammogram. The dense glandular tissue will look white, and fatty tissue will look dark on your mammogram. The more white areas the radiologist sees on the image, the denser the breast.

Management and Treatment

Does breast density change over time?

Breast density can change throughout a woman’s life. For some women, the breasts may become more fatty (less dense) as they get older. Others may have increased density – for example, density may increase in women who use hormone replacement therapy in the post-menopausal years. Some women may have no change in their density.

Care at Cleveland Clinic


Is there an increased risk of breast cancer if I have dense breast tissue?

There may be a slightly increased risk for breast cancer if you have dense breast tissue. Healthcare professionals have not yet been able to prove why that is. Having dense tissue can also make it harder for radiologists to see breast cancer because it can be hidden by the similar appearing dense tissue.

What are the risk factors for breast cancer?

Breast cancer is a common type of cancer affecting women. The cause of breast cancer is usually unknown, which makes understanding risk factors very important. Some of the risk factors can include:

  • Family history
  • Age (the risk increases as you age)
  • Personal history of cancer
  • Having other breast lesions
  • Alcohol use
  • Childbirth (particularly first child) after age 30
  • Hormone therapy after menopause
  • Being overweight

Living With

Do I still need to get mammograms if I have dense breast tissue?

It is recommended that you still get regular mammograms even if you have dense breast tissue. It is important to discuss both your breast density and your risk factors for breast cancer with your healthcare provider when deciding when to start and how often to get regular mammograms. If you have dense tissue, your doctor may also suggest a tomosynthesis/3D exam, in addition to your usual mammogram to ensure that you are being thoroughly screened for breast cancer.

Last reviewed by a Cleveland Clinic medical professional on 08/07/2019.


  • American Cancer Society. Breast Density and Your Mammogram Report. ( Accessed 8/8/2019.
  • The American College of Obstetricians and Gynecologists. Breast Density. ( Accessed 8/8/2019.
  • The American College of Radiology. Breast Density: Breast cancer screening. ( Accessed 8/8/2019.
  • National Breast Cancer Foundation. Breast Anatomy. ( Accessed 8/8/2019.
  • Radiological Society of North America, Dense Breast. ( Accessed 8/8/2019.

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