Gynecomastia; Breast enlargement in a male
When abnormal breast tissue develops in males, it is called gynecomastia. It is important to find out if the excess growth is breast tissue and not excess fat tissue (lipomastia).
The condition may occur in one or both breasts. It begins as a small lump beneath the nipple, which may be tender. One breast may be larger than the other. Over time the lump may become less tender and feel harder.
Enlarged breasts in males are usually harmless, but may cause men to avoid wearing certain clothing or to not want to be seen without a shirt. This can cause significant distress, particularly in young men.
Some newborns may have breast development along with a milky discharge (galactorrhea). This condition usually lasts for a couple of weeks to months. In rare cases, it may last until the child is 1 year old.
Normal hormone changes are the most common cause of breast development in newborns, boys, and men. There are other causes as well.
Breast enlargement is usually caused by an imbalance of estrogen (female hormone) and testosterone (male hormone). Males have both types of hormones in their body. Changes in the levels of these hormones, or in how the body uses or responds to these hormones, can cause enlarged breasts in males.
In newborns, breast growth is caused by being exposed to estrogen from the mother. About one half of boy babies are born with enlarged breasts, called breast buds. They usually go away in 2 to 6 months, but can last longer.
In preteens and teens, breast growth is caused by normal hormone changes that occur in puberty. More than one half of boys develop some breast enlargement during puberty. Breast growth often goes away in about 6 months to 2 years.
In men, hormone changes due to aging can cause breast growth. This may occur more often in overweight or obese men and in men age 50 and older.
Certain health problems can cause breast growth in adult men, including:
Rare causes include:
MEDICINES AND MEDICAL TREATMENT
Some medicines and treatments that can cause breast growth in men include:
DRUG AND ALCOHOL USE
Using certain substances can cause breast enlargement:
Gynecomastia has also been linked to exposure to endocrine disrupters. These are common chemicals often found in plastics.
Men who have enlarged breasts may have an increased risk for breast cancer. Breast cancer in men is rare. Signs that may suggest breast cancer include:
For swollen breasts that are tender, applying cold compresses may help. Ask your health care provider if it's OK to take pain relievers.
Other tips include:
Call your provider if:
If your son has breast growth but has not yet reached puberty, have it checked by a provider.
Your provider will take a medical history and perform a physical examination.
You may not need any tests, but the following tests may be done to rule out certain diseases:
Often no treatment is needed. Breast growth in newborns and young boys often goes away on its own.
If a medical condition is causing the problem, your provider will treat that condition.
Your provider will talk with you about medicines or substances that may cause breast growth. Stopping their use or changing medicines will make the problem go away. DO NOT stop taking any medicines before talking to your provider.
Breast growth that is large, uneven, or does not go away may cause a decrease in quality of life. Treatments that may be used in this situation are:
Gynecomastia that has been present for a long time is less likely to resolve even if the right treatment is started.
Ali O, Donohoue PA. Gynecomastia. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 603.
Anawalt BD. Gynecomastia. In: Jameson JL, De Groot LJ, de Kretser DM, et al, eds. Endocrinology: Adult and Pediatric. 7th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 140.
Sansone A, Romanelli F, Sansone M, Lenzi A, Di Luigi L. Gynecomastia and hormones. Endocrine. 2017;55(1):37-44. PMID: 27145756 pubmed.ncbi.nlm.nih.gov/27145756/.BACK TO TOP
Review Date: 10/2/2020
Reviewed By: Brent Wisse, MD, board certified in Metabolism/Endocrinology, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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