Dense Breast Tissue on a Mammogram: Meaning and Results


As part of your mammogram results, you may learn you have dense breast tissue. This is not abnormal; however, it can increase the risk of breast cancer. It is more difficult to see through dense tissue clearly on a mammogram, increasing the risk of missing breast cancer on a screening. 

Learn more about dense breast tissue and why you may need additional screening tests to detect problems within the tissue.

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About Breast Tissue

Breasts consist of different types of tissues. These include the milk ducts and lobes involved in making milk and transporting it out of the body to feed a baby. Fat cells, also called adipose tissue, make up another type of breast tissue. Each breast has a different amount of tissue, accounting for normal variability in breast size and shape.

Three Types of Tissue

The breasts contain three different types of tissue:

  • Fatty tissue: breast tissue that is not dense and primarily consists of fat cells
  • Glandular tissue: breast tissue that includes the lobes (responsible for milk production) and ducts (what the milk travels through to reach the nipple)
  • Fibrous tissue, which holds the breast tissue together and is considered supportive or connective tissue

Sometimes glandular and fibrous tissues are combined, called fibroglandular tissue.

What Is Dense Tissue?

Breast tissue that is not fatty is considered dense tissue. Glandular and fibrous tissues are dense tissue, including milk ducts, glands, and connective tissues.

Breast density is categorized into one of four groups:

  • Extremely dense: In about 10% of women, the entire breast is very dense.
  • Heterogeneously dense: In about 40% of women, dense tissue spreads evenly across the breast.
  • Scattered fibroglandular density: In about 40% of women, specific areas of the breast have dense tissue.
  • Almost entirely fatty breast tissue: In about 10% of women, the entire breast is fatty.

Risk Factors for Dense Breast Tissue

While any woman can have dense breast tissue, some factors increase the risk. For example, women with a lower body mass index (BMI) with smaller breasts are more likely to have dense breast tissue because there is less proportionate fat tissue than dense tissue. Additionally, women tend to gain more fatty breast tissue as they age, so younger women are at an increased risk of having dense breast tissue. Post-menopause hormone therapy can also increase breast density.

Dense Tissue and Breast Cancer Risk

There is an increased risk of breast cancer among women with dense breast tissue. Additionally, it is more difficult to detect and diagnose breast cancer in women with dense breast tissue because it is harder to see cancerous or potentially cancerous areas on imaging.

However, there are no adapted screening recommendations as there are for women with other risk factors, such as having a BRCA1 or BRCA2 gene mutation. There is not enough evidence to support that dense breast tissue increases the risk enough for different screening recommendations.

Screenings for Dense Breast Tissue

It is important to determine if you have dense breast tissue in case additional breast cancer testing is required.

Tests to check for dense breast tissue include:

A screening mammogram is the most common way to detect dense breast tissue.


A mammogram is a type of X-ray used specifically for the breast. It uses images of the breast tissue to screen for breast cancer in hopes of detecting it early and improving outcomes. Mammograms can also detect dense breast tissue. Different mammograms include screening mammograms (preventive) and diagnostic mammograms (used once abnormalities are detected).

3D Mammography

A 3D mammogram, or digital breast tomosynthesis, can provide more varied images than a traditional mammogram because it photographs the breast while moving over it in an arc.

Compared to 2D mammograms, 3D mammograms are more effective in detecting invasive cancer.

For women with dense breast tissue, 3D mammography may be especially beneficial as it can help detect potential cancer that is more likely missed on a 2D mammogram. However, women with dense breast tissue tend to get called back for additional screening just as often with 3D mammogram results as with 2D mammogram results.


A breast ultrasound is a type of screening that gets images of the breast tissue from sound waves using a machine on the skin. This screening may be used for women with dense breast tissue to help identify potential breast cancer that may not be visible on 2D or 3D mammograms.

One drawback of a breast ultrasound is that it is more likely than a mammogram to detect a false positive (testing positive for a condition that is not actually present).

Breast Magnetic Resonance Imaging (MRI)

A breast MRI takes images of breast tissue using a machine with magnets and radio waves. It may be used as a supplemental screening tool in conjunction with a mammogram in women with dense breasts, as it is more likely than a mammogram to produce false positives. However, it can detect cancer that other methods miss, such as in women with dense breast tissue.


A breast biopsy is when breast tissue is tested in a lab for cancer by removing a small piece of the tissue. A biopsy may be recommended if previous screening identified potentially cancerous tissue. Surgery is not always necessary for a breast biopsy.

Several biopsy methods test breast tissue, including:


Breasts come in a variety of shapes, sizes, and densities. About half of all women have dense breast tissue, which mammogram imaging can detect. While dense breast tissue is often completely normal, it can increase women’s risk of breast cancer. Breast cancer may be harder to detect in women with dense breast tissue, as it’s more difficult to see through dense tissue on screening images.

Women with dense breast tissue may be advised to get additional testing after a screening mammogram; this does not mean cancer has been detected. However, it is essential to follow recommendations for further screening to rule out breast cancer.

A Word From Verywell

Receiving any type of abnormal result on a medical test, such as a mammogram, can be difficult. Remember that dense breast tissue is very common and does not mean you have breast cancer. Follow recommendations for additional testing to rule out breast cancer, and seek support from your healthcare provider throughout the process.

Frequently Asked Questions

  • How often should you get a mammogram if you have dense breasts?

    How often a woman should get a mammogram depends on the combination of her specific risk factors, including age and genetic risk. There are no particular screening guidelines for dense breast tissue alone, but some women are recommended to get yearly mammograms. Speaking with a healthcare provider about risks and screening recommendations is essential.

  • Can you make breasts less dense?

    Breasts tend to naturally become less dense with age. Additionally, post-menopause hormone therapy may increase breast density, so stopping treatment may decrease breast density. Always talk with a healthcare provider before discontinuing any medication or treatment.

  • Is it better to have fatty or dense breasts?

    Women with dense breasts have an increased risk of breast cancer compared to those with fatty breasts; however, fatty breast tissue is more commonly linked to obesity, increasing the risk of many health concerns, including breast cancer. Speak to your healthcare provider about screening to learn about your specific risk factors.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Ashley Olivine

By Ashley Olivine, Ph.D., MPH

Dr. Ashley Olivine is a health psychologist and public health professional with over a decade of experience serving clients in the clinical setting and private practice. She has also researched a wide variety psychology and public health topics such as the management of health risk factors, chronic illness, maternal and child wellbeing, and child development.


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