Medical Encyclopedia


Medical Encyclopedia

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Contents of this page:



Alternative Names    Return to top

Breast development in a male

Definition    Return to top

Gynecomastia is the development of abnormally large breasts in males.

Considerations    Return to top

The condition may occur in one or both breasts and begins as a small lump beneath the nipple, which may be tender. The breasts often enlarge unevenly. Gynecomastia during puberty is not uncommon and usually goes away over a period of months.

In newborns, breast development may be associated with milk flow (galactorrhea). This condition usually lasts for a couple of weeks, but in rare cases may last until the child is 2 years old.

Causes    Return to top

The most common cause of gynecomastia is puberty.

Other causes include:

Rare causes include:

Home Care    Return to top

Apply cold compresses and use analgesics as your health care provider recommends if swollen breasts are also tender.

When to Contact a Medical Professional    Return to top

Call your health care provider if the breasts have developed abnormally or if there is swelling or pain in one or both breasts.

Note: Gynecomastia in children who have not yet reached puberty should always be checked by a health care provider.

What to Expect at Your Office Visit    Return to top

Your health care provider will take a medical history and perform a physical examination.

Medical history questions may include:

Testing may not be necessary, but the following tests may be done to rule out certain diseases:


If an underlying condition is found, it is treated. Gynecomastia during puberty usually goes away on its own; however, persistent, extreme, or uneven breast enlargement may be embarrassing for an adolescent boy. Breast reduction surgery may be recommended.

After seeing your health care provider:

If your health care provider made a diagnosis related to gynecomastia, you may want to note that diagnosis in your personal medical record.

Update Date: 12/6/2007

Updated by: Nancy J. Rennert, M.D., Chief of Endocrinology Diabetes, Norwalk Hospital, Associate Clinical Professor of Medicine, Yale University School of Medicine, New Haven, CT. Review provided by VeriMed Healthcare Network.

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