Anatomy of the Breasts Each breast has 15 to 20 sections (lobes), which are arranged like the petals of a daisy. Each lobe has many smaller lobules, which end in dozens of tiny bulbs that can produce milk. Normal Breast Development and Changes Breast development occurs in distinct stages, first before birth, and again at puberty and during the childbearing years. Changes also occur to the breasts during menstruation and when a woman reaches menopause. Risk Factors for Breast Cancer Factors that appear to raise a woman's risk for breast cancer include advancing age, family history, benign breast conditions, and a late menopause. Breast Health: Three-Step Plan for Preventive Care To monitor your breast health, you should do a monthly breast self-exam, get a year clinical exam, and get mammograms as directed by your doctor. How to Perform a Breast Self-Examination (BSE) By doing BSE regularly, you get to know how your breasts normally feel so that you are more apt to detect any change.