Gynaecomastia (sometimes referred to as 'man boobs') is a common condition that causes boys' and men's breasts to swell and become larger than normal. It is most common in teenage boys and older men.
Gynaecomastia (sometimes referred to as 'man boobs') is a common condition that causes boys' and men's breasts to swell and become larger than normal. It is most common in teenage boys and older men.
Signs vary from a small amount of extra tissue around the nipples to more prominent breasts. It can affect one or both breasts.
Sometimes, the breast tissue can be tender or painful, but this isn't always the case.
Gynaecomastia can be caused by an imbalance between the sex hormones testosterone and oestrogen. Oestrogen causes breast tissue to grow. While all men produce some oestrogen, they usually have much higher levels of testosterone, which stops the oestrogen from causing breast tissue to grow.
If the balance of hormones in the body changes, this can cause a man's breasts to grow. Sometimes, the cause of this imbalance is unknown.
Being very overweight (
) is a common cause of gynaecomastia – this is because being overweight can increase levels of oestrogen, which can cause breast tissue to grow. If you're overweight you're also more likely to have excess fat that can enlarge the breast tissue. For some people losing weight or doing more exercise can help but this may not always improve the condition.Gynaecomastia can affect newborn baby boys, because oestrogen passes through the placenta from the mother to the baby. This is temporary and will disappear a few weeks after the baby is born.
During
, boys' hormone levels vary. If the level of testosterone drops, oestrogen can cause breast tissue to grow. Many teenage boys have some degree of breast enlargement. Gynaecomastia at puberty usually clears up as boys get older and their hormone levels become more stable.As men get older, they produce less testosterone. Older men also tend to have more body fat, and this can cause more oestrogen to be produced. These changes in hormone levels can lead to excess breast tissue growth.
Other rare causes of gynaecomastia include:
See a doctor if you're worried about breast tissue growth – they can discuss the treatment options with you.
If a doctor thinks you need treatment, they may recommend:
Always see a doctor if the area is very painful or there's an obvious lump. Sometimes, the lump may need to be removed. Gynaecomastia isn't related to
, but you should see a doctor if you're worried about breast swelling.Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.