Breast development in a male

Alternative names

Gynecomastia is the development of prominent breast tissue in the male.

The most common cause of gynecomastia in the male is puberty. The condition may occur in one or both breasts and begins as a small lump beneath the nipple, which may be tender. The breasts often enlarge unevenly. Gynecomastia during puberty is not uncommon, is self-limiting, and usually goes away over a period of months.

In newborns, breast development may be associated with milk flow (galactorrhea). This condition usually lasts for a couple of weeks and in rare cases may persist until the child is two years old. It is caused by exposure to maternal hormones.

Other causes of gynecomastia include chronic liver disease, kidney failure, and exposure to estrogens, androgens (often taken secretly for body building), marijuana, and some medications. Rare causes include tumors, genetic defects, or an overactive thyroid.

Common Causes

  • Puberty  
  • Exposure to estrogen hormone  
  • Exposure to androgen hormones  
  • Marijuana use  
  • Tumors  
  • Genetic disorders  
  • Chronic liver disease  
  • Kidney failure  
  • Side effects of some medications

Home Care
Apply cold compresses and use analgesics as recommended by the health care provider if swollen breasts are also tender.

Call your health care provider if
Call your health care provider if the breasts have developed abnormally or if there is swelling or pain in one or both breasts.

Note: Gynecomastia in children who have not yet reached puberty should always be evaluated by a health care provider.

What to expect at your health care provider’s office
The medical history will be obtained and a physical examination performed.

Medical history questions documenting gynecomastia may include:

  • Is one or both breasts involved?  
  • What is the age and gender of the patient?  
  • What medications are being taken?  
  • How long has gynecomastia been present?  
  • Is the gynecomastia staying the same, getting better, or getting worse?  
  • What other symptoms are also present?

Testing is not normally necessary, but the following tests may be performed to rule out disease cause:

  • Blood hormone level tests  
  • Breast ultrasound  
  • Liver and kidney function studies  
  • Mammogram

Although spontaneous resolution is normal, persistent breast enlargement may be embarrassing for an adolescent boy. On occasion, breast development may be so great that surgery is recommended to prevent emotional damage.

After seeing your health care provider:
If a diagnosis was made by your health care provider related to gynecomastia, you may want to note that diagnosis in your personal medical record.

Johns Hopkins patient information

Last revised: December 3, 2012
by Martin A. Harms, M.D.

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.