Reproductive and Sexual Health Handbook

Breast tissue begins to develop in both men and women at the time of fetal development. For women, increased circulating oestrogen, working together with growth hormone⁽¹⁾ at the onset of puberty, heralds the onset of sexually dimorphic breast development.

The adult woman’s breast (Figure 5.1) is composed of a mixture of adipose and glandular tissue. The glandular component includes lobules (responsible for milk production after pregnancy) and ducts which carry the milk to the nipple during lactation. Hormonal fluctuations influence the amount of glandular tissue present. This is most pronounced during pregnancy and lactation. As women approach menopause, glandular tissue shrinks and is replaced by fat. The cyclical nature of women’s hormonal stimulation of the breast brings with it cyclical changes in the size and texture of the breast. It is usually during the menstrual cycle that most women will complain of breast symptoms, the nature of which will be highly variable.

Figure 5.1 The Breast

This figure is reproduced with permission of © The StayWell Company, LLC

Most breast symptoms are due to benign breast disease which commonly presents as breast lumpiness, lumps and/or pain. The primary challenge for the clinician is to exclude breast cancer.