Breasts are mainly made up of glandular, fibrous and fatty tissue. They sit on the front of the chest and go up into the armpit.
Breast tissue is supported by ligaments (which attach deeper layers of tissue to the skin) and the large chest muscle that extends over most of the ribs.
The glandular tissue contains lobes, with many smaller lobules inside each one. The lobules are the milk-producing glands. During pregnancy, breast milk is carried through tubes called ducts to the nipple ready for breastfeeding.
The darker area of skin around the nipple is called the areola. On the areola there are some little raised bumps called Montgomery glands. They produce fluid to moisturise the nipple.
Normal breast changes
Your breasts change constantly throughout your life from puberty, through adolescence, the childbearing years and then the menopause (when periods stop permanently). This is because of the varying levels of the female hormones oestrogen and progesterone in your body.
Before a period
Oestrogen and progesterone play a vital part in regulating a woman’s periods. These hormones are responsible for the changes you may notice in your breasts just before your period.
Your breasts may feel heavier and fuller. They may also be tender or lumpy. After a period, this usually lessens or disappears altogether, although some women have tender, lumpy breasts all the time.
Many women also have breast pain linked to their menstrual cycle (cyclical breast pain), which is normal. For more information see our Breast pain booklet.
Breast changes can be an early sign of being pregnant. Many women feel a change in sensation in their breasts such as tingling and soreness (particularly of the nipples). This is due to increased levels of progesterone and the growth of the milk ducts. The breast and the areola begin to get bigger. The nipple and areola become darker and remain that way during pregnancy.
Large amounts of milk are produced to breastfeed a newborn baby and the breasts can change size many times a day according to the baby’s feeding pattern. Nipples can sometimes become sore and cracked, but this generally gets better over time. When breastfeeding stops, the breasts gradually go back to how they were before pregnancy although they may be a different size and less firm than before. For more information see our Breast changes during and after pregnancy booklet.
Before, during and after the menopause
From around the mid-30s onwards the breasts begin to age and the glandular and fibrous tissue is gradually replaced by fat. As oestrogen levels fall during and after the menopause, the breasts may change size, lose their firmness, feel softer and may droop. Changes, such as a lump or tenderness, are also common at this time. Lumps often turn out to be breast cysts (fluid-filled sacs). Tenderness may be non-cyclical breast pain, which may need to be treated with pain relief.
It’s still important to see your GP (local doctor) about any changes that are new for you, even though for most women these will be benign (not cancer).
Wearing a well-fitting bra
A woman’s breasts change size and shape many times during her life, due to the menstrual cycle, pregnancy and breastfeeding, the menopause and putting on or losing weight. Wearing a well-fitting bra can help if you are feeling any discomfort or back pain. For more information see our Your guide to a well-fitting bra leaflet.
Breast changes can be a sign of a benign breast condition that may need treatment although some breast changes do not.
For example, breast pain linked to your periods is common and usually regarded as normal. However, talk to your GP if it’s severe and long lasting.
Find out more about benign breast conditions