Gynecomastia: Prominent Male Breasts

Gynecomastia. ADAM Medical Encyclopedia

What is Gynecomastia?

Gynecomastia is a benign male breast condition in which a male has one or two prominent breasts. This condition does not increase a man's risk of developing male breast cancer. Gynecomastia is one of the symptoms of Klinefelter's syndrome.

What are Symptoms of Gynecomastia?

A small, button-shaped lump of breast tissue can be felt under the male nipple, causing tenderness. The male breasts may enlarge unevenly during puberty, as hormones cause overall body changes.

Gynecomastia is common during puberty and usually disappears after a few months.

Most Common Causes of Gynecomastia:

  • Puberty (hormonal growth and changes during adolescence)
  • Estrogen exposure (female hormone present in the body and the environment)
  • Androgen exposure (bodybuilding hormones)
  • Marijuana use
  • Medication side effects

Impact on a Male:

Gynecomastia is a benign (non-cancerous) condition, however, some men who have prominent breasts, or uneven breasts, often feel some embarrassment about their body image. This condition can also cause emotional conflict over sexual identity.

Treatment Options:

If male breasts are tender as a result of gynecomastia, cold compresses may be applied. Analgesics (pain relievers) may also be used. In the case that there is extra swelling or pain in either or both male breasts, call your doctor for a clinical evaluation. If the condition persists beyond puberty, plastic surgery for breast reduction may be considered.

How does Gynecomastia relate to Klinefelter's syndrome?

Gynecomastia is only one symptom of Klinefelter's syndrome, a condition in which a male has an extra X chromosome. Males usually have one X and one Y chromosome. Some of the other clinical findings associated with Klinefelter's are hypothyroidism, infertility, and testicular cancer.

Klinefelter's syndrome is associated with an increased risk of developing male breast cancer. But if you have gynecomastia, this condition alone does not increase your risk of male breast cancer.


Medline Plus, a Service of National Institutes of Health. "Gynecomastia" Last revised date: 27 February 2006. Medline Plus (NIH)

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