What Do Dense Breasts Look Like & What Its Causes?

Dense breast tissue is pretty common and is very normal. Approximately 40-50% of women have a dense breast tissue ( and they are in categories C and D), while only 10% of women are within the category D or “Extremely dense” breast tissue group. Now, what do dense breasts look like? What causes dense breast tissue? Read below to know about them.

Dense Breasts: A Brief Introduction

It is normal and common to find dense breast tissue or the appearance of breast tissues on the mammogram. Milk glands, the milk ducts along with the supportive tissue or the dense breasts tissue, and the non-dense breasts tissue or the fatty tissue all together form the breast tissue. While viewing on a mammogram; women having dense breasts generally have more dense tissues than the fatty tissue.

It is important to consider the breast density, because having dense breasts affects you in two primary ways. First is, it increases your risk of breast cancer(though it is still unknown why); and second is, it increases the chance of breast cancer going undetected by a mammogram, as dense tissue can really mask a potential cancer.

What Do Dense Breasts Look Like & What Its Causes?

What Do Dense Breasts Look Like?

There is a misconception about dense breasts and that is, these dense breasts are firm or are large. However, for a woman with firm breasts, it is not necessary to have dense breasts. It must be noted that a woman’s breasts density can actually change over time. For citing an example, as a woman grows with age, there occur some hormonal changes and that may result in the development of more fatty tissues in her breasts.

Non-dense breast tissue on a mammogram appears transparent and dark. However, the dense breast tissue looks like a solid white area on the mammogram and this makes it tough to see through.

The levels of density of breasts in women are assigned by the radiologists who analyze their mammogram and determine the ratio of non-dense tissue to their dense tissue. We must make you aware that the levels of breasts density are described with the use of a, results reporting system known as the BI-RADS or breast Imaging Reporting and Data System. The breasts density levels are usually recorded in the mammogram report of a woman with the help of letters (A, B, C and D). The different breasts density levels are:

Level A:

Here, it looks almost completely fatty, indicating that the breasts are mostly composed of fat entirely. About 1 woman in every 10 women has level A- breast density.

Level B:

It shows scattered areas of the fibroglandular density, indicating there are few scattered areas of density; however the non-dense breasts tissue forms the majority. About 4 women in every 10 women show Level B dense breast density.

Level C:

These are heterogeneously dense and this indicates that though there are some areas of non-dense tissue; yet most of the breasts tissue is dense. About 4 women in every 10 women have this level C of dense breast density.

Level D:

These are the extremely dense categories that almost all of the breasts tissue in women is dense. About 1 woman in every 10 shows level D dense breast density.

It is to be informed that those women who have breasts classified as heterogeneously or the extremely dense breasts are considered to be having dense breasts, about half of women who undergo mammograms, are found to have dense breasts.

What Causes Dense Breast Tissue?

It is like the younger you are, the denser your breasts are, and as you age, your breasts tend to become more fatty but less dense. This change in the breast density occurs due to a decline in your estrogen hormone levels, as a part of the natural process of aging, especially during the menopause phase.

Now, talking about the dense breasts, in the United States, about 50% to 60% of women in between the age group of 40 years to 44 years are considered to have dense breasts. What exactly causes dense breast tissue?

Well, though it is not clear why some women are having a lot of dense breast tissue while other women don’t have; yet, in most of the cases the breast tissue density is due to genetics. It means those women who have dense breasts are mostly likely to have their mothers and grandmothers with dense breasts too.

But again, it is always essential to know that dense breast tissue is not constant and it may change over time. Younger women, premenopausal women, and women those taking a combination hormone therapy for treating menopause symptoms are most likely to have dense breasts tissues. Apart from this, some studies also suggest that factors like diet and life style also may affect the breast tissue density; however, those are not exactly definitive.

It is also found that women having a lower body mass index or women having less body fat are more likely to have denser breast tissues compared to the women who are overweight or obese.


As we already mentioned that a dense breast tissue might be associated with the risk of getting cancer; so it is always essential for you to go for the best possible screening for cancer and know about your condition if you feel you have dense breasts. Though a mammogram report may not be able to detect if it is the dense breast tissue or breast cancer developing; still mammogram is the best way to detect and catch cancer in your breasts as early as possible. Digital Breast Tomosynthesis or DBT, or the 3D mammograms offer radiologists to see the possible changes on the mammogram, even in dense breast tissues. Apart from this there are also few other ways to detect breast cancers such as ultrasound or an MRI; however they may also generate false positives and may also carry other health risks.

It is thus always important to talk about the importance and risks of these tests including the mammography and routine screening.

NOTE: Not every woman having dense breasts has breast cancer.

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Team PainAssist
Team PainAssist
Written, Edited or Reviewed By: Team PainAssist, Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:March 27, 2019

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