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What Dense Breast Tissue Means for Your Health

October 12, 2025

Dense breast tissue is something you might see on a mammogram report. But what does it really mean, and why does it matter for your health?

We asked Danielle Heller, MD, a breast surgical oncologist with Hartford HealthCare Cancer Institute, to walk us through it.

Here’s what you should know.

1. Dense breast tissue is normal

Having dense breast tissue is extremely common, especially before menopause — in fact, about 40% of women have dense breasts.

Breast density refers to how much fibroglandular tissue — the tissue that makes and carries milk — you have compared to fatty tissue.

“Because most breast cancer starts in the fibroglandular breast cells, having dense breasts can raise the risk of developing breast cancer – but it’s just one piece of your overall risk profile,” Dr. Heller explains. “Age, family history, lifestyle and genetics also play a role.”

> Related: 4 Signs of Perimenopause (and How to Manage It)

2. Dense tissue can make breast exams trickier

Self-breast exams are always important, but density isn’t something you can feel.

“Technically, density is a radiologic finding,” says Dr. Heller. “But many women have fibrocystic, ‘lumpy-bumpy’ tissue that can make exams more challenging.”

That’s why it helps to know your baseline — how your breasts normally look and feel — so you can spot any changes early.

> Related: 7 Symptoms of Breast Cancer You May Not Know

3. Density affects mammogram accuracy

Dense breast tissue isn’t rare — and it can make mammograms a little harder to interpret.

“A majority of women have dense breast tissue on their mammograms,” Dr. Heller says. “Dense breast tissue shows up as white, or radio-opaque. Because breast masses may also look radio-opaque, dense tissue lowers the sensitivity of mammograms to detect cancer.”

Tissue density has a graded scale from “mostly fatty” to “extremely dense.” And since 2023, mammogram reports are required to tell you your density – so it’ll be in your results.

> Related: 5 Mammogram Myths That Shouldn’t Stop You From Being Screened

4. You may need additional screening

If your doctor recommends extra imaging, it doesn’t necessarily mean something is wrong – it just means more information is needed.

If you have dense breasts, your doctor may offer a breast ultrasound or even an MRI.

“Ultrasound is widely available, radiation-free and uses sound waves to show the texture of breast tissue,” says Dr. Heller. “MRI is less common but highly effective, using contrast dye to highlight areas of blood flow that could signal cancer.”

> Related: At What Age Should I Start Getting Mammograms? 

5. Breast density changes over time

Breast tissue usually becomes less dense as you get older, especially after menopause.

“As women age, fatty tissue in the breast tends to increase while fibroglandular tissue decreases,” Dr. Heller says. “This has to do with lower basal estrogen levels and less stimulation of fibroglandular tissue.”

This shift in density also makes mammograms easier to read.

6. Talk with your doctor about dense breasts

If your mammogram mentions dense breast tissue, bring it up with your provider.

“Dense breast tissue is common, but it’s important to be aware of it,” says Dr. Heller. “Your care team can help decide if additional imaging is needed to boost the accuracy of screening.”

“Knowing your density helps you and your doctor make the best plan for your breast health.”