Home › Health Topics › Illnesses & Health Problems > 
Search Topics

Male breasts at puberty - (gynaecomastia)

breasts; gynecomastia; hormone; puberty; male; boy; nipple; gynaecomastia; man; boobs ;

One of the unexpected changes that can happen to boys during puberty is that their breasts can start to grow. This is a common and normal part of development of males, but it is rarely talked about and it can cause a lot of worry.

When boys develop breast tissue around puberty and in their teen years it does not need any treatment. It will go away as they get older.


About 65% of normal healthy males have growth of some breast tissue around puberty. It is caused by the hormones that lead to the other changes of puberty.

During puberty boys often demand privacy so parents may not see the changes, and their son may be quite unwilling to let them know. Boys probably will not be able to talk with their friends about it either, and they can be very worried about it, wondering if they have cancer for example, or whether or not they are normal boys.

  • Gynaecomastia (guy-nee-co-mas-ti-a) is the medical term for breast tissue growing on a male.
  • Many very young male babies have some breast tissue due to hormones from their mothers, but this usually goes away within a few weeks. Baby girls often have this also, and their breasts flatten too in a few weeks.
  • Breast tissue growth ('man boobs') for older males can be caused by using some drugs such as anabolic steroids, other health problems, or by medicines that are needed to treat some health problems. Overweight men can have 'man boobs', but these are due to fat deposits, not to growth of breast tissue. These are not the cause of breast tissue growth for young men around puberty.

What does it look like?

  • It normally looks like a slight build up under the nipples. One breast may develop on its own, or both may grow a little. Sometimes it can be tender or itchy.
  • It starts like breast development does for girls, but it stops when it is still a small lump. It does not keep growing.
  • Even though it may be very obvious to the boy, most other people will not notice it.
  • It should be hardly noticeable under clothes.

If they are worried about how it looks when they take their top off, for example when going swimming, they could wear a t-shirt or 'rashie', which will protect other parts of their body getting sun burnt too, which is always good!

How long will it last?

  • It is always temporary, and the boy's breasts will flatten again.
  • The swelling usually goes down within a year or two, and it is almost always gone before the age of 20 years.

Should he see a doctor?

  • It would be best for anyone who is worried about his health to talk to someone.
  • A doctor can examine your son and make sure that there is no other (rare) reason for the growth of the breast tissue. It is rare that any tests will be needed.
  • Your doctor will be able to answer any other questions you may have.

More about male breasts

Family doctor 

Teenshealth from the Nemours Foundation

back to top

The information on this site should not be used as an alternative to professional care. If you have a particular problem, see a doctor, or ring the Parent Helpline on 1300 364 100 (local call cost from anywhere in South Australia).

This topic may use 'he' and 'she' in turn - please change to suit your child's sex.

Home › Health Topics › Illnesses & Health Problems >