Breast density tends to decrease as a woman ages.As she gets older the dense ducts and lobules (glandular tissue) get replaced by fatty tissue.

• 乳房的致密度会随著年岁的增加而减少，当年龄增长时，乳房中的乳腺管和乳小叶组织(腺体组织)会逐渐被脂肪替代。