Dense Breast Tissue: What Every Woman Needs to Know (and Why It Matters for Mammogram Accuracy)

Group of diverse women wearing pink tops, standing in a circle with their hands extended inward, holding a pink breast cancer awareness ribbon.

IF YOU’VE ever had a mammogram, chances are you felt a sense of relief when the results came back normal. For many women, this test is a key part of staying proactive about their health. But what if you did everything right—got your mammogram, followed the guidelines—and yet something was still missed?

That’s the reality for many women with what’s known as dense breast tissue—a common but often overlooked condition that can interfere with accurate cancer detection through standard mammograms. Until recently, most women didn’t even know they had it, because radiologists weren’t required to share that information. Thankfully, that’s beginning to change.

What Is Dense Breast Tissue and Why Does It Matter?

Breasts are made up of a mix of fatty, fibrous, and glandular tissue. If you have more of the fibrous and glandular types, your breasts are considered “dense.”

Key Facts About Dense Breast Tissue:

  • Dense breast tissue is common. Around 40–50% of women over age 40 have it.

  • It’s completely normal—especially in younger women—but it can complicate screening.

  • You can’t feel dense tissue. It can only be seen through imaging, not through self-exam or a physical exam.

  • Dense tissue makes mammograms less accurate. Both dense tissue and cancer appear white, making it harder to detect abnormalities.

  • Up to 1 in 3 cancers may be missed on a mammogram in women with dense breasts.

  • It also increases your risk. Women with extremely dense breasts are 4–6 times more likely to develop breast cancer.

  • Mammograms are still essential, but for women with dense breasts, they may not be enough.

  • Supplemental screenings like whole breast ultrasound and MRI can be life-saving and should be actively pursued.

A Step Toward Change: New Laws Around Breast Density Notifications

For a long time, whether or not a woman was told she had dense breast tissue depended on where she lived. But in 2023, the U.S. Food and Drug Administration (FDA) stepped in to create a nationwide standard. Now, all mammography facilities are required to notify patients if they have dense breasts and recommend that they speak with their healthcare provider about additional screening options.

This shift didn’t happen overnight. It came thanks to the women who bravely spoke up, shared their painful experiences, and fiercely advocated for greater awareness and transparency. Their courage created real change, and we honor them with deep gratitude. Because of their efforts, patients today have more information—and more power—to make informed decisions about their care.

What Screening Looks Like in the U.S. Today:

  • Annual mammograms are recommended starting at age 40 for most women

  • Imaging facilities are now legally required to notify you if your mammogram shows dense breast tissue

  • Supplemental imaging is not automatically offered—it typically requires your provider to recommend or order it, which is why being informed and proactive matters

What Are Your Screening Options for Dense Breast Tissue?

When more detail is needed, these tools can be added alongside mammograms to improve detection and peace of mind:

Whole Breast Ultrasound

  • Gentle, advanced imaging that scans the entire breast—including underarms—with no compression or radiation

  • Especially helpful for women with dense breasts, implants, or surgical scarring

  • Provides consistent, high-resolution imaging

  • Used in addition to, not instead of, mammograms

  • Services like HerScan bring this technology directly into communities through mobile clinics, making it easier and more affordable to access. They make stops a few times a year in Dallas. You can check availability online here.

Breast MRI

  • Very sensitive imaging that can detect abnormalities missed on mammograms or ultrasound

  • Often recommended for women with a strong family history, genetic mutations (like BRCA1 or BRCA2), or other high-risk factors

  • Involves contrast dye to highlight areas of concern by showing blood flow patterns

  • Typically used for high-risk screening or when more clarity is needed

What’s Next: Understanding the Root Causes of Dense Breast Tissue

Dense breast tissue is incredibly common—but what causes it in the first place? While genetics play a role, hormones—especially estrogen—are believed to be a major factor. In an upcoming blog post, I’ll explore how hormone levels, environmental exposures, and lifestyle factors may contribute to dense breast tissue—and what you can do to support breast health naturally.

In the meantime, if you’ve been told you have dense breasts, know this: you are not alone, and there are tools available to help you take the next best step for your health. Supplemental screenings like whole breast ultrasound and MRI can offer peace of mind, better clarity, and—most importantly—early detection.

The more we know, the better we can advocate for ourselves and each other. You deserve clarity, access, and care that truly supports your whole being.

Further Reading + Resources