Medically reviewed by Katharine Maglione, MD
The phrase “dense breast tissue” can be confusing. Is it normal? Is it something to worry about? About half of women over 40 have dense breasts. Many people wonder what that means for their health and their next mammogram.
What is dense breast tissue?
Breasts are made of fat and fibroglandular breast tissue. Breast density means how much breast tissue you have compared with fat. A radiologist, who is a doctor trained to read medical images, places breast density into one of four groups. You cannot tell your breast density by how your breasts look or feel. It only shows up on a mammogram.
On a mammogram, dense tissue looks white. Tumors can also look white. Fat looks dark. This can make it harder to see an unusual area when there is a lot of dense tissue in the image.
Why does breast density matter?
Breast density matters for two reasons. First, dense tissue can make a tumor harder to see on a mammogram. Second, dense breasts are linked to a slightly higher risk of breast cancer. These are two separate issues. Both are worth discussing with your doctor.
Healthcare practices are required to send you a letter in the mail after your mammogram, telling you whether you have dense breasts. If you received that letter and have not looked at it in a while, bring it to your next appointment.
What does additional screening look like?
Doctors may suggest more screening for some women with dense breasts. This is in addition to a mammogram. One option is an ultrasound. It uses sound waves to make pictures of the breast. It can sometimes find lumps that are hard to see on a mammogram. Doctors may suggest it when breast density is the only added risk factor.
Another option is a breast MRI. An MRI uses magnets and a special dye to make detailed images. It may also find areas that look concerning but are not cancer. Doctors often suggest an MRI for women with dense breasts and another risk factor. This could include a strong family history of breast cancer or a BRCA1 or BRCA2 gene mutation.
These tests do not replace a mammogram. Mammograms can still find small changes, such as tiny calcium spots, that other tests may miss. They remain an important tool for finding breast cancer early.
What should you ask your doctor about dense breasts?
Breast density is one piece of information. Your age, family history and any genetic testing also matter. Your doctor can help you understand what your mammogram report means for you. Together, you can decide if you need an ultrasound, MRI or regular mammograms only.
If you have not talked about breast density with your doctor yet, your next appointment is a good time to ask. Learn more about WMCHealth’s women’s health services and schedule an appointment.