Category a

Almost entirely fatty tissue

Category b

Scattered areas of dense tissue

Category c

Increased presence of dense tissue

Category d

Mostly dense tissue in breasts

Percent Density by Age Group

*Statistics provided by a study by Cheka et al. published in AJR 2012. 

of women in their 40s

of women in their 50s

of women in their 60s

of women in their 70s

Only 1 in 5 women know density reduces mammography accuracy

While mammography is the way to determine breast density currently, mammography misses 50% of cancer in dense breasts. Six major studies showed ultrasound coupled with mammography increased cancer detection rates from 48% to 97% in women with dense breast tissue.

*Data provided by a study by Guterbock et al. published in JACR 2016

Additional Resources

There is a broad range of resources to learn about breast health, diseases that affect the breast, breast tissue density, recommended testing guidelines for breast cancer screening, breast cancer types, and breast cancer treatment options.

Below are a few web links to organizations of the many that are available.