Gynecomastia is the swelling of the breast tissue in boys or men, caused by an imbalance of the hormones estrogen and testosterone. Gynecomastia can affect one or both breasts, sometimes unevenly. Newborns, boys going through puberty and older men may develop gynecomastia as a result of normal changes in hormone levels, though other causes also exist. Generally, gynecomastia is not a serious health condition, but it can be tough to cope with. Men and boys with gynecomastia sometimes experience pain in their breasts.

Signs and symptoms of gynecomastia include:

  • Swollen breast gland tissue
  • Breast tenderness

See your doctor if you have swelling, a palpable mass, pain, tenderness or nipple discharge in one or both breasts.

Gynecomastia is triggered by a decrease in the amount of the hormone testosterone compared with estrogen. Several things can upset the hormone balance. The hormones, testosterone, and estrogen control the development and maintenance of sex characteristics in both men and women. Testosterone controls male traits, and estrogen controls female traits, including the growth of breasts. Most people think of estrogen as an exclusively female hormone, but men also produce it (normally in small quantities). However, male estrogen levels that are too high or are out of balance with testosterone levels can cause gynecomastia. Gynecomastia during puberty is also seen. Gynecomastia caused by hormone changes during puberty is relatively common. In most cases, the swollen breast tissue will go away without treatment within six months to two years.

A number of medications can cause gynecomastia. These include:

  • Anti-androgens used to treat prostate enlargement, prostate cancer, and some other conditions. Examples include flutamide, finasteride (Proscar, Propecia) and spironolactone (Aldactone).
  • Anabolic steroids and androgens.
  • AIDS medications. Gynecomastia can develop in HIV-positive men who are receiving a treatment regimen called highly active antiretroviral therapy (HAART). Efavirenz (Sustiva) is more commonly associated with gynecomastia than are other HIV medications.
  • Anti-anxiety medications, such as diazepam (Valium).
  • Antibiotics.
  • Ulcer medications, such as cimetidine (Tagamet HB).
  • Cancer treatment (chemotherapy).
  • Tricyclic antidepressants.
  • Heart medications, such as digoxin (Lanoxin) and calcium channel blockers.
  • Gastric motility medications, such as metoclopramide (Reglan).

Substances that can cause gynecomastia include:

  • Alcohol
  • Amphetamines
  • Marijuana
  • Heroin
  • Methadone

Several health conditions can cause gynecomastia by affecting the normal balance of hormones. These include:

  • Hypogonadism: Any of the conditions that interfere with normal testosterone production, such as Klinefelter’s syndrome or pituitary insufficiency, can be associated with gynecomastia.
  • Aging: Hormone changes that occur with normal aging can cause gynecomastia, especially in men who are overweight.
  • Tumors: Some tumors, such as those involving the testes, adrenal glands or pituitary gland, can produce hormones that alter the male-female hormone balance.
  • Hyperthyroidism: In this condition, the thyroid gland produces too much of the hormone thyroxine.
  • Kidney Failure: About half the people being treated with regular hemodialysis experience gynecomastia due to hormonal changes.
  • Liver Failure and Cirrhosis: Hormonal fluctuations related to liver problems as well as medications taken for cirrhosis are associated with gynecomastia.
  • Malnutrition and Starvation: When your body is deprived of adequate nutrition, testosterone levels drop, but estrogen levels remain constant, causing a hormonal imbalance. Gynecomastia can also occur once normal nutrition resumes.

Your healthcare professional will ask you questions about your medical and drug history and what health conditions run in your family. The doctor will also do a physical examination that may include careful evaluation of your breast tissue, abdomen, and genitals.

Initial tests to determine the cause of your gynecomastia may include: blood tests, mammograms, computerized tomography (CT) scans, magnetic resonance imaging (MRI) scans, testicular ultrasounds or tissue biopsies.

Your healthcare professional will want to be sure your breast swelling is actually gynecomastia and not another condition. Other conditions that can cause similar symptoms include:

  • Fatty Breast Tissue: Some men and boys have chest fat that resembles gynecomastia. This is called false gynecomastia (pseudogynecomastia), and it is not the same as gynecomastia.
  • Breast Cancer: This is uncommon in men, but can occur. Enlargement of one breast or the presence of a firm nodule raises the concern for male breast cancer. See Male Breast Cancer.
  • A Breast Abscess (Mastitis): This is an infection of the breast tissue.

Most cases of gynecomastia regress over time without treatment. However, if it is caused by an underlying condition, such as hypogonadism, malnutrition or cirrhosis, that condition may require treatment. If you are taking medications that can cause gynecomastia, your doctor may recommend stopping them or substituting another medication.

In adolescents with no apparent cause of gynecomastia, the doctor may recommend periodic re-evaluations every three to six months to see if the condition improves on its own. Gynecomastia often goes away without treatment in less than two years. However, treatment may be necessary if it does not improve on its own or if it causes significant pain, tenderness or embarrassment.

If you still have significant bothersome breast enlargement despite initial treatment or observation, your doctor may advise consultation with a plastic surgeon. Gynecomastia surgery reduces breast size in men, flattening and enhancing the chest contours. In severe cases of gynecomastia, the weight of excess breast tissue may cause the breasts to sag and stretch the areola (the dark skin surrounding the nipple). In these cases, the position and size of the areola can be surgically improved and excess skin may be reduced.

Plastic surgery to correct gynecomastia is technically called reduction mammoplasty, and unfortunately is generally not covered by medical insurance.