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Pronounced: gi-ne-KOH-mast-e-ah

En Español (Spanish Version)


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).



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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

Risk Factors

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.


Prevention of gynecomastia requires avoiding known risk factors. Thus, avoiding excessive alcohol consumption, avoiding steroids, and refraining from marijuana use will prevent gynecomastia from those sources.


American Academy of Family Physicians

National Library of Medicine


BC Health Guide

Men's Health Centre


Enlarged breasts in men (gynecomastia). Mayo Clinic website. Available at: . Accessed January 13, 2008.

Gynecomastia. EBSCO DynaMed website. Available at: . Accessed January 13, 2008.

Gynecomastia: when breasts form in males. American Academy of Family Physicians website. Available at: . Accessed Accessed January 13, 2008.

Modest GA. Gynecomastia. In: Noble JN, ed. Textbook of Primary Care Medicine . 3rd ed. St. Louis, MO: Mosby, Inc.; 2001: 185-187.

Wise GJ. Male breast disease. Am Coll Surg . 2005;200:255-269.

Last reviewed January 2008 by Adrienne Carmack, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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