So, you’ve just gotten your first mammogram (congrats!) — but the report mentions that you have “dense breasts.”

Um, what?

It’s quite normal to feel a pang of fear when you see that detail mentioned in your mammogram results. (FWIW, that’s what happened to me when I got the news that I have dense breasts). Suddenly you’re wondering, “Is there something wrong with my boobs? Does this mean I’m at a higher risk for breast cancer?”

No, there’s nothing wrong with your boobs. About 50% of women have dense breast tissue — so, pretty normal, right? But, just because this is a common condition, that doesn’t mean you should ignore your dense breasts, especially when it comes to breast cancer screenings. 

What does it mean to have dense breasts?

“Having dense breasts can make it harder to detect small cancers using mammography alone, and also increases your risk of developing breast cancer,” explains Robyn Roth, M.D., a board-certified radiologist specializing in breast imaging, and known across social media as @theboobiedocs.

Okay, so how can we find out if we’re in the dense-breast club? Can we feel the dense breast tissue during a self-exam? How will this affect our breast cancer screenings? Fear not, fellow dense breasties: Rescripted spoke to Dr. Roth at length about this topic, and she’s got us covered. 

What does dense breast tissue feel like?

While “dense breast tissue may feel lumpy or nodular at different points during your menstrual cycle,” Dr. Roth says the only way to know for certain if you have dense breasts is through mammography. So schedule that mammogram if you’re due for one!

Dr. Roth says dense breasts are predominantly hereditary, but some factors can contribute to an increase or decrease of breast density. Losing weight, pregnancy or breastfeeding, radiation therapy, and certain medications containing estrogen may increase breast density. Gaining weight and normal aging may decrease breast density.

How radiologists determine if you have dense breasts

Dense breast tissue is determined by assigning your breasts into one of four categories “depending on the amount of fibroglandular tissue versus fat,” says Dr. Roth. This categorization occurs in the section of your mammogram report labeled “breast composition.”

The breakdown is as follows:

a. fatty (<25%)
b. scattered (25-50%)
c. heterogeneously dense (50-75%)
d. extremely dense (>75%). 

For those categorized as either “heterogeneously dense" or "extremely dense" breast tissue, “then you have greater than 50% fibroglandular tissue, and [your breasts] are considered to be dense,” says Dr. Roth.

Dense breast tissue and breast cancer

If you have dense breasts, it is critical to make a breast cancer screening plan with your healthcare provider. “We now know that dense breast tissue is an independent risk factor for developing breast cancer,” says Dr. Roth. “The more dense breast tissue you have, the greater the chances you will eventually develop breast cancer.”

Although mammography is the only way to confirm dense breast tissue, this form of breast cancer screening isn’t always the best method for patients with dense breasts  at least not by itself. That’s because dense breast tissue appears white on a mammogram, and so do cancers. “Dense breast tissue can possibly obscure small breast cancers,” explains Dr. Roth. “Think of it like trying to find a snowflake in a blizzard; the more snow you have, the harder it is to find a single snowflake.”

Dr. Roth goes on to say that “mammography alone can miss up to 50% of breast cancers in women with dense breast tissue,” so it’s a good idea to consult with your medical provider about adding either a supplemental ultrasound or MRI – depending on your risk factors – to your breast cancer screening plan. That way, “radiologists are better able to see through the dense tissue and assess if there is an underlying abnormality.” 

Breast cancer screening guidelines

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Even if you don’t have dense breast tissue, breast cancer screenings are imperative for women. Dr. Roth recommends getting a mammogram at age 40 if you are at average risk, and repeating this imaging every one to two years (“annual mammography saves the most lives”).

She also advises that all women have a breast cancer risk assessment before age 30 (“ideally at age 25”). This is to “identify high-risk individuals who may benefit from earlier or supplemental imaging.”

If you are at high risk — meaning you have a greater than 20% lifetime risk of breast cancer — Dr. Roth recommends beginning MRIs as early as age 25, and mammography as early as age 30, alternating every six months. “A good rule of thumb is 10 years before a first-degree relative who was diagnosed with breast cancer,” she says.

As always, if you are at high risk for breast cancer — whether it’s due to family history or dense breasts — make sure to have a conversation with your physician about your best course of action. While supplemental imaging may result in the discovery of something that, per Dr. Roth, “may warrant a follow-up or a minimally invasive biopsy to exclude cancer,” having that ultrasound or MRI in addition to a mammogram could mean the discovery of breast cancer “at the earliest, most treatable stage.”

Sarene Leeds holds an M.S. in Professional Writing from NYU, and is a seasoned journalist, having written and reported on subjects ranging from TV and pop culture to health, wellness, and parenting over the course of her career. Her work has appeared in Rolling Stone, The Wall Street Journal, Vulture, SheKnows, and numerous other outlets. A staunch mental health advocate, Sarene also hosts the podcast “Emotional Abuse Is Real.” Visit her website here, or follow her on Instagram or Twitter.