Gynecomastia is enlargement of the breasts in men. It is relatively common, occurring in about one third of men.

About 65% of boys develop some degree of breast enlargement during puberty. This is normal and usually goes away by age 18.

The breast tissue is firm in men with gynecomastia. In contrast, the breast tissue is soft in men with fat on their chests, hence looking like enlarged breasts (fatty enlargement of the breasts).

Men normally produce much more male hormones (androgens) than female hormones (estrogens). Gynecomastia is caused by an imbalance in the female and male hormones. The hormone imbalance can be caused by:

• Aging
• Testosterone deficiency
• Certain medications, such as digoxin (a heart medication), spironolactone (a diuretic), cimetidine (a medication for stomach conditions), and many others
• Anabolic steroids used to enhance athletic performance in sports
• Marijuana use
• Liver or kidney failure
• Chronic kidney disease
• Hyperthyroidism (overactive thyroid gland)
• Tumors of the testicles, lung, stomach, liver, kidney, or pituitary gland

A risk factor is something that increases your chance of getting a disease or condition.

By definition, only men can get gynecomastia.

Risk factors:

• Age: over 50
• Obesity
• Excess alcohol consumption leading to liver cirrhosis
• Chronic liver or kidney disease
• Presence of a condition or medication that decreases androgen or estrogen production
• Family history

Symptoms of gynecomastia include:

• Enlargement of the breasts with firm tissue, usually on both sides
• Tenderness

Your doctor will ask about your symptoms and medical history, and perform a physical exam . You may need to be referred to a doctor who specializes in hormone disorders (an endocrinologist).

Your doctor will be especially interested in other symptoms you have had and your use of medications. He or she will focus on your weight, breast exam, testicular exam, and any other signs of a hormone problem.

Diagnostic tests may include:

• Blood sample—to check the function of your liver, thyroid, and kidneys, as well as other hormone levels
• Ultrasound —a test that uses sound waves to examine the breasts
• CT scan —a type of x-ray that uses a computer to make pictures of the breasts
• Biopsy —If the diagnosis or cause remains unclear, a sample of breast tissue may be removed and sent to a pathology laboratory for evaluation.

Usually treatment for gynecomastia is not needed. However, it is important to find and treat the underlying cause of the gynecomastia. For example, if you are taking a medication that causes gynecomastia, your doctor will ask you to discontinue it or change to a different medication if possible. It is particularly important to exclude tumors as a cause of gynecomastia, and, if one is found to be present, to treat it.

If treatment of gynecomastia is needed, medications are sometimes used, though they can produce unwanted side effects. On rare occasions, surgery is used to remove breast tissue.