Gynaecomastia is the enlargement of male breast tissue. It’s a common, benign (not cancer) condition that mainly affects teenage boys and older men, but it can affect men at any age.

Even though gynaecomastia is very common, it’s not talked about much because some people, particularly boys, find it embarrassing.

Gynaecomastia can often make teenage boys feel very anxious and worry about what it means for them. Two out of three teenage boys develop some degree of gynaecomastia, and 90% of cases get better by themselves.

The symptoms of gynaecomastia can vary from a small, firm enlargement of breast tissue just behind the nipple to a larger, more female-looking breast. Gynaecomastia can affect one or both breasts. The area can be tender to touch or painful.

True gynaecomastia (caused by an enlargement of breast tissue) is different from pseudo-gynaecomastia, which is an increase in fatty tissue. However, gynaecomastia can also be a mixture of both.

Last reviewed: March 2015
Next planned review begins 2018

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