Trusted medical advice from the
American Academy of Family Physicians.


What is gynecomastia?

Gynecomastia is a condition in which men have enlarged breasts. It is caused by an increase in breast tissue, not fat tissue. Gynecomastia may be present in one or both breasts.

Both boys and men can have the condition. It can occur in newborns as well. Some men or boys have excess fat that looks like breasts. This is known as pseudogynecomastia. It is a similar, but different condition than gynecomastia.

Symptoms of gynecomastia

The main symptom of gynecomastia is enlarged breasts. Your breasts may be tender, as well. You may feel a slight bump or lump behind the nipple.

What causes gynecomastia?

The main cause of gynecomastia is a change in hormones. Most often, this happens at birth, puberty, or as part of aging. These are natural times when the hormones in your body change levels. An imbalance of hormones—estrogen and testosterone—can enlarge your breasts.

Newborns who are born with enlarged breasts often have too much estrogen. Mothers transfer this hormone to their babies in the womb.

Gynecomastia is common in teenage boys. More than half of boys have some degree of the condition during puberty.

In adult men, the balance of hormones is affected by aging. Gynecomastia is more common in men who are 50 years of age or older. Other causes include health conditions, such as:

  • Tumors of the adrenal gland, pituitary gland, or testes
  • Hyperthyroidism (overactive thyroid)
  • Hypogonadism (low testosterone)
  • Kidney disease
  • Liver disease

It can also be caused by medicines, such as:

  • HIV/AIDS medicines
  • Chemotherapy and radiation
  • Antibiotics
  • Medicines for heart disease
  • Anti-anxiety medicines
  • Tricyclic antidepressants
  • Ulcer and heartburn medicines, such as proton pump inhibitors (PPIs)

Another potential cause is drugs, such as:

  • Opioids
  • Anabolic steroids
  • Amphetamines
  • Heroin
  • Marijuana

Gynecomastia can also be caused by other lifestyle factors including obesity, alcohol use, and the consumption of estrogen in medicines or in foods that contain soy.

It is very rare for breast cancer to be the cause of gynecomastia. Lumps caused by cancer do not form in breast tissue behind the nipple. The lumps also feel different than those caused by gynecomastia. Other signs of breast cancer are dimpling of the skin and bloody discharge from the nipple.

How is gynecomastia diagnosed?

Make an appointment with your doctor if you have concerns. Your doctor may notice symptoms during a routine check-up. They may ask about your symptoms, such as how long you’ve had the tissue growth and if the area is tender. Your doctor also may ask about your health history and what medicines you take.

The doctor will decide if tests are needed to diagnose gynecomastia. The most common test is a blood test to check your hormone levels. More tests may be done if your doctor suspects a disease. These can include:

  • An ultrasound
  • Mammogram
  • Breast biopsy

Can gynecomastia be prevented or avoided?

Most cases of gynecomastia cannot be prevented. They are caused by natural changes in hormone levels. Adults can help prevent gynecomastia by avoiding certain medicines, drugs, and lifestyle factors.

Gynecomastia treatment

In most cases, treatment is not needed. Your doctor may want to check the size of your breast tissue every few months.

If treatment is needed, options vary based on the cause of the condition. Talk to your doctor before stopping any prescription medicine to treat other medical conditions. Stop taking illegal drugs. You may need to make lifestyle changes as well. If it caused by a disease or tumor, you will need to treat the problem. This may include medicine or surgery. Medicine can help to balance your hormones. In rare cases, the doctor may suggest plastic surgery to remove the extra breast tissue.

Living with gynecomastia

For most newborns and teenage boys, gynecomastia does not last long. The breasts go back to normal in 6 months to 2 years.

Ask the doctor about taking an over-the-counter pain medicine to relieve breast tenderness. Using a cold compress on the area can help as well.

Questions to ask your doctor

  • What is the likely cause of gynecomastia?
  • How do I know if a certain medicine or drug is the cause?
  • Do I have a health condition or disease that is causing enlarged breasts?
  • Should I be tested for breast cancer?
  • Will I need treatment?
  • How long will it take for the breast growth to return to normal?
  • Is there anything I can do to feel better until gynecomastia goes away?
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