Definition of Gynecomastia:

Gynecomastia is the development of abnormally large breasts in males.

Considerations:

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.

Common Causes:

The most common cause of gynecomastia is puberty.

Other causes include:

• Chronic liver disease
• Exposure to anabolic steroid hormones
• Exposure to estrogen hormone
• Genetic disorders
• Kidney failure
• Marijuana use
• Side effects of some medications
• Testosterone (male hormone) deficiency

Rare causes include:

• Genetic defects
• Overactive thyroid
• Tumors