Gynecomastia


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Editors
Bradley D. Anawalt, MD
Caroline J. Davidge-Pitts, M.B., B.Ch.
Glenn D. Braunstein, MD
Alvin M. Matsumoto, MD


Additional Resources
Mayo Clinic
MedlinePlus

What is gynecomastia?
Gynecomastia is breast enlargement in boys or men due to a benign (non-cancerous) increase in breast tissue. This condition results from an imbalance between the hormones testosterone and estrogen. Although gynecomastia doesn’t cause health problems, it can make breasts tender.

Who develops gynecomastia?
Gynecomastia is common in newborn boys due to exposure to their mother’s estrogen. It can also occur in boys going through puberty. In both cases, it usually goes away on its own. In adults, it’s most common in men over the age of 50 years. It may affect only one, or both breasts.

What causes gynecomastia in adults?
A number of factors can cause enlarged breast tissue in men, however, sometimes no cause is
found:

  • The hormonal changes of aging (having less testosterone and more estrogen)
  • Increased body fat, which can increase estrogen levels
  • Medicines and other substances:
    • Medicines that prevent the production or block the action of testosterone, such as treatment for prostate cancer
    • Certain antibiotics
    • Anti-ulcer drugs
    • Some cancer treatments (chemotherapy)
    • Some medicines for heart and blood vessel disease
    • Some medicines for psychiatric conditions, such as anxiety, depression, and psychotic disorders
    • Alcoholic beverages (drinking too much)
    • Illegal drugs: amphetamines, anabolic steroids and androgens (used by some bodybuilders or athletes to improve performance), heroin, and marijuana
    • Some over-the-counter drugs, herbal supplements with phytoestrogens (plant substances that are like estrogen), and lotions, such as those containing lavender or tea tree oil

    Some health problems:

    • Conditions that result in low testosterone levels
    • Overactive thyroid gland (hyperthyroidism)
    • Liver disease
    • Kidney disease and kidney failure
    • Certain tumors

How is gynecomastia diagnosed?
Your doctor will ask questions about your medical conditions and usual medicines, including over-the-counter medicines. In a physical exam, your doctor will check your breast tissue to see if the enlargement is gynecomastia or another condition. Other causes of enlarged breasts include fat deposits, benign tumors, and fluid-filled pouches (cysts). The doctor will look for signs of breast cancer, a rare condition in men. Your doctor also will check your testicles for size and for the presence of a tumor.

Your doctor may recommend other tests:

  • Blood tests to check hormone levels
  • Tests to see whether the liver, kidneys, and thyroid are working properly
  • A mammogram to rule out breast cancer

What is the treatment for gynecomastia?
In some cases, no treatment is needed. In other cases, the treatment depends on the factors causing the enlargement. If a medicine or other substance is the cause, your doctor may recommend you stop using it, or switch you to a different medicine. If a disease is the cause, you will be treated for the disease as needed.

Other treatments include:
Medicines that block the effect of estrogen in breast tissue (especially for men who have had gynecomastia for a short time). These medicines, however, are not approved for this indication by the FDA. Please talk to your physician about what this means.

Surgery to remove breast tissue (especially for men who have a lot of breast tissue or who have had gynecomastia for a long time).

Questions to ask your doctor

  1. Why are my breasts enlarged?
  2. What are my options for treatment?
  3. Should I see a male reproductive specialist (urologist)?

Edited: May 2018