About our breasts
Women's breasts are designed to produce milk after pregnancy. Breast tissue is made up of milk glands, supportive fibrous tissue, fatty tissue, arteries, veins, lymph vessels and nerves. The milk glands consist of lobules, where milk is made, and ducts, which take the milk to the nipple.
The breast tissue extends from the collarbone down to the bottom of the bra line, and from the middle of the chest to the middle of the armpit.
There is no such thing as a ‘perfect' or ‘normal' breast shape or size. Women's breasts and nipples come in all shapes and sizes. It is common for one breast to be slightly bigger than the other and normal for the texture of our breasts to change as we get older.
Our breasts change throughout our lifetime. Many changes are caused by our reproductive hormone levels. Hormone levels change when we have our periods, pregnancies and menopause, and as we age.
In young women breasts are dense, glandular structures designed for producing milk. As we age they gradually become less glandular and more fatty. By the time our periods stop and we pass menopause, our milk glands have been almost completely replaced by fat. Thus, as we get older our breasts become softer and less lumpy.
Monthly periods also cause our breasts to change. They may feel swollen, tender or lumpy just before a period begins. This is normal and due to changes in hormone levels. It is normal for breast tissue to grow a little and fill with fluid before having a period. This swelling goes down when the level of hormones falls as our period begins. These normal changes continue every month until we reach menopause. After menopause the use of hormone replacement therapy may also cause changes to breasts.
During pregnancy our breasts also change. Breasts grow an average of two cup sizes during pregnancy. Tenderness is common in the early stages of pregnancy. Breastfeeding can also cause conditions such as mastitis (a painful breast infection), breast pain and cracked nipples.
Although most breast changes or problems are benign (not cancerous), many women worry that they might be a sign of breast cancer. It is important that a doctor checks all unusual breast changes, just to be sure.
Expert content reviewers:
Dr Meron Pitcher (Chair VCOG Breast Cancer Committee), Surgeon, Western Hospital