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Gynecomastia

What is gynecomastia?

Gynecomastia is a swelling of the breast tissue in men or boys. The breasts become larger. They may grow unevenly.

Gynecomastia often happens when a preteen or teenage boy is going through the hormonal changes of puberty. But it can also happen to newborn babies and to older men.

What causes gynecomastia?

Gynecomastia is usually a benign (non-cancerous) condition. It may be linked to many different causes of hormone changes. In some cases, the cause isn’t known.

Gynecomastia is often caused by changes in levels of the female hormone (estrogen) and the male hormone (testosterone). But it can be caused by other things as well.

Gynecomastia can be a side effect of medicines used to treat prostate cancer. These medicines change your testosterone levels. Illegal drugs can also cause gynecomastia.

Some diseases and medical conditions may also cause gynecomastia. These include:

  • Liver diseases
  • Lung cancer
  • Testicular cancer
  • Tumors of the adrenal glands or pituitary gland
  • Some conditions that a baby is born with (congenital disorders)
  • Thyroid disorders
  • Injury or trauma

Newborn babies may have a short-term form of gynecomastia. This is often because a mother’s estrogen stays in a baby’s blood for a while after birth.

Gynecomastia is not linked to breast cancer. It is rare that men get breast cancer. But your provider may do some tests to rule out breast cancer.

What are the symptoms of gynecomastia?

You may have gynecomastia in 1 or both breasts. It starts as a lump beneath the nipple, which may be sore. The breasts often get larger unevenly.

The symptoms of gynecomastia may look like other medical conditions or problems. Always see your health care provider for a diagnosis.

How is gynecomastia diagnosed?

Your provider will take your past health and give you a physical exam.

To rule out other diseases or conditions, you may also have tests including:

  • Blood tests, including liver function tests and hormone studies
  • Urine tests
  • A low-dose X-ray of your breast (mammogram)
  • A small breast tissue sample (a biopsy) may be removed and checked for cancer cells

 In some cases, tests are not needed to diagnose the condition

Your provider may suggest that you see a provider who specializes in hormones and how they affect many organs (an endocrinologist).

How is gynecomastia treated?

Your health care provider will create a care plan for you based on:

  • Your age, overall health, and past health
  • How serious your case is
  • How well you handle certain medicines, treatments, or therapies
  • If your condition is expected to get worse
  • What you would like to do

Most cases of gynecomastia happen during puberty. The condition usually gets better on its own without treatment. This may take from 6 months to 2 or 3 years.

If a medicine is causing your breast enlargement, stop taking the medicine. That can solve the problem. If a disease is causing the condition, the disease will need to be treated.

Hormone therapy may be used to treat gynecomastia.

In rare cases, surgery may be used to remove the extra tissue.

Key points

  • Gynecomastia is a swelling of the breast tissue in men or boys.
  • The breasts become larger. They often grow unevenly.
  • It is often caused by changes in levels of the female hormone (estrogen) and the male hormone (testosterone). Other things may cause it as well.
  • Most cases happen when a preteen or teenage boy is going through puberty. But it can also happen to newborn babies and older men.
  • It often goes away on its own. In some cases, hormone therapy is needed.

Next steps

Tips to help you get the most from a visit to your health care provider:

  • Before your visit, write down questions you want answered.
  • Bring someone with you to help you ask questions and remember what your provider tells you.
  • At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you.
  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your provider if you have questions.