Condition Basics

What is gynecomastia?

Gynecomastia is the overdevelopment of the male breast. A breast has both glandular tissue and fatty tissue. With gynecomastia, the glands in the breast become enlarged. The enlarged glands may feel like a rubbery disk beneath the nipple area. Both breasts are often affected.

What causes it?

Gynecomastia may be caused by an imbalance of hormones in your body. It can happen from normal hormone changes during infancy, puberty, or as men age. Or it may be caused by a medical condition or taking certain medicines.

Newborns may have enlarged breasts when they are first born because they received hormones from their mother.

Preteen and teen boys may develop gynecomastia from rapid changes in their hormone levels during puberty.

Men can develop gynecomastia from age-related hormone changes if their testosterone level drops too low. Or it can be caused by a medical condition, like chronic liver disease. There are also medicines that can cause this, such as hormone therapy for prostate cancer and medicines used to treat high blood pressure or heart problems.

Taking steroids for bodybuilding can also cause gynecomastia. But sometimes it occurs for no known reason.

What are the symptoms?

In addition to having enlarged breasts, men or boys with gynecomastia may notice their breasts feel rubbery or firm. Often men don't have any symptoms. Boys may notice a lump or mass behind the nipple. Boys (and some men) may have breast tenderness and pain. Some breast enlargement is common in adolescent boys during puberty. But it is usually temporary and goes away without treatment.

How is it diagnosed?

Gynecomastia can usually be diagnosed from a physical examination and medical history. Tests that may be done to rule out breast cancer include ultrasound, mammogram, and a breast biopsy. Other lab tests, such as a blood test, may be done to check hormone levels.

Gynecomastia in newborn babies often goes away in a few weeks without treatment. But it can last for up to a year.

If gynecomastia occurs during puberty, it often goes away within a year without treatment. But it may last for up to 2 years. It can be uncomfortable. But if it causes pain or worry, medicine or surgery can help.

When the condition is caused by medicines, treatment involves changing or stopping the medicine. If it's caused by another medical problem, treating the other condition will help balance hormones and may reduce the gynecomastia.

Men who have prostate cancer and get hormone therapy may take medicines or have radiation for gynecomastia.

For teens and men with severe gynecomastia, early treatment with medicines can make a difference. Breast tissue can change in less than a year from glandular tissue to fibrotic tissue. Once that happens, surgery may be the only way to reduce the extra breast tissue.