What does this mammogram result mean if dense?

Common in your age: Many younger women have dense breasts on mammograms. This means more glandular tissue. In older women there is more fatty tissue and the mammogram is actually better. A mammogram with dense breast tissue at 42 is not abnormal, and not a major source for concern.

Dense breasts: "Dense" breasts are normal, but decrease the sensitivity of the mammo for detecting cancers. Breasts are dense when there is a increase in normal fibroglandular stroma relative to breast fat. Also, dense breasts are an independent risk factor for developing breast cancer.