Medically Reviewed By William C. Lloyd III, MD, FACS

What is gynecomastia?

Gynecomastia refers to a condition in which males develop swelling of breast tissue. It should not be confused with pseudogynecomastia, in which adipose (fat) tissue takes on the appearance of breasts. Gynecomastia is not uncommon, especially in pubescent males and male infants. Gynecomastia arises from changes in androgen and estrogen levels, which control the development of male and female characteristics, respectively.

Gynecomastia often starts as a tender lump below the nipple. Lumps are generally small in size. The development of breast tissue can occur on one or both sides, and growth can occur unevenly. In certain cases, such as in infants, galactorrhea (milk production) can occur along with gynecomastia.

Gynecomastia can arise from heredity, lifestyle, and developmental factors. Gynecomastia may occur in up to half of males undergoing puberty. In addition, it is common in bodybuilders, those who use steroids, and marijuana users. It may also be related to conditions such as thyroid imbalance.

In most cases, gynecomastia will resolve spontaneously. In situations in which bodybuilding or recreational drug use leads to breast tissue development, addressing the underlying cause of gynecomastia will often resolve the condition. In rare cases, however, gynecomastia may require hormone therapy or breast reduction surgery.

While gynecomastia is common and is generally not serious, seek prompt medical care for symptoms that may indicate breast cancer, such as breast development on only one side, firm lumps within the breast, ulcers of the breast, or bloody nipple discharge.

Seek prompt medical care for prepubescent males with symptoms of gynecomastia, as these may indicate a serious underlying condition.

What are the symptoms of gynecomastia?

The usual symptoms of gynecomastia include lumps under the nipple on either one or both sides of the torso, breast development, and tenderness of the breasts. In more serious cases, symptoms of gynecomastia include painful breasts, skin ulceration over the breast, or nipple discharge. Seek medical attention for any serious symptoms of gynecomastia, as these could be early indicators of breast cancer.

Common symptoms of gynecomastia

You may experience gynecomastia symptoms daily or just once in a while. At times any of these symptoms can be severe:

  • Breast development
  • Lumps under the nipple
  • Nipple discharge or tenderness

Serious symptoms that might indicate a serious condition

In some cases, gynecomastia can be related to breast cancer. Seek prompt medical care if you, or someone you are with, have symptoms including:

  • Bloody nipple discharge
  • Breast lump that is firm and unmovable (fixed)
  • Painful lumps within a single breast
  • Skin ulcerations of the breast

What causes gynecomastia?

Gynecomastia is caused by changes in the level of androgens (male hormones) in the body, as may occur during puberty. Fluctuations in androgen levels can occur for a variety of reasons.

Developmental causes of gynecomastia

Gynecomastia is common over the course of development, especially when hormone fluctuations occur, such as during:

  • Aging

  • Infancy

  • Puberty

Disease causes of gynecomastia

In addition to developmental causes, androgen fluctuations may occur as a result of disease or disease treatment, such as:

  • Hyperthyroidism (overactive thyroid)

  • Hypogonadism (decreased activity of the gland that produces sex hormones)

  • Kidney or liver failure

  • Liver disease (includes any type of liver problem, such as hepatitis, cirrhosis and liver failure)

  • Medication side effects, including side effects of hormone treatments, chemotherapy, radiation therapy, and certain medications (spironolactone, tricyclic antidepressants, omeprazole, cimetidine, phenytoin, griseofulvin)

  • Tumors of androgen-producing glands, such as adrenal glands or testes

Lifestyle causes of gynecomastia

Certain lifestyle factors can also play a role in the development of gynecomastia including:

  • Alcohol abuse

  • Amphetamine or heroin use

  • Marijuana use

  • Anabolic steroid use

What are the risk factors for gynecomastia?

A number of factors increase the risk of developing gynecomastia. Not all people with risk factors will get gynecomastia. Risk factors for gynecomastia include:

  • Cancer (testicular, adrenal, liver, carcinoid)

  • Family history of hormone imbalance

  • Hyperthyroidism (overactive thyroid)

  • Hypogonadism (decreased activity of the gland that produces sex hormones)

  • Kidney or liver failure

  • Liver disease (includes any type of liver problem, such as hepatitis, cirrhosis and liver failure)

  • Puberty

  • Steroid or illegal drug use

  • Susceptibility to known side effects of prescription medications

Reducing your risk of gynecomastia

In some cases, gynecomastia can arise from hormone imbalances due to behavioral causes. You may be able to lower your risk of gynecomastia by:

  • Avoiding marijuana

  • Avoiding steroids not prescribed by your doctor

  • Ceasing use of bodybuilding supplements and drugs

How is gynecomastia treated?

In most cases, especially in pubescent males and infants, gynecomastia resolves itself. In extreme cases, medical intervention, such as hormone therapy or even breast reduction surgery, may be required. In cases in which there is an underlying cause, such as steroid abuse, treatment of the underlying cause generally leads to resolution of gynecomastia.

What you can do to improve your gynecomastia

If gynecomastia is leading to discomfort, certain self-care measures may be helpful including:

  • Stopping recreational drug and bodybuilding supplement use
  • Taking over-the-counter pain medication
  • Using a cold compress

What are the potential complications of gynecomastia?

Gynecomastia does not generally lead to complications. In rare cases, gynecomastia may be linked to breast cancer, although breast cancer and gynecomastia are separate conditions. In some people, especially pubescent males, complications of untreated gynecomastia can be serious. You can help minimize your risk of serious complications by following the treatment plan you and your health care professional design specifically for you. Complications of gynecomastia include:

  • Chronic pain/discomfort
  • Embarrassment
  • Skin ulcerations of the breast
Was this helpful?
  1. Gynecomastia. Medline Plus, a service of the National Library of Medicine National Institutes of Health.
  2. Gynecomastia.
  3. Kahan S, Miller R, Smith EG (Eds.). In A Page Signs & Symptoms, 2d ed. Philadelphia: Lippincott, Williams & Williams, 2009.
  4. Braunstein GD. Clinical practice. Gynecomastia. N Engl J Med 2007; 357:1229.
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Jan 16
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