Gynecomastia is when male breast tissue swells and becomes unusually large. It is a common condition that stems from a change in balance between the hormones testosterone and estrogen.

Males and females have breast glands, but they are not usually noticeable in males.

Breast gland enlargement may affect males of all ages, including newborns, during puberty, and older adults. Gynecomastia is the result of additional breast tissue rather than fat. Exercising or losing weight will not reduce the breast tissue in gynecomastia.

Pseudogynecomastia is a separate condition where fat builds up in the breasts, possibly due to a person being overweight or having obesity.

The breast consists of firm and dense glandular tissue and softer fatty tissue.

The ratio of glandular to fatty tissue in breasts varies between individuals. A male with gynecomastia may have too much of both types of tissue.

Liposuction can remove excess fatty tissue. It involves inserting a small tube through an incision. Excision involves cutting out tissue with a scalpel to remove excess glandular tissue. This will normally leave a scar around the edge of the nipple.

If a major reduction in tissue and skin is necessary, the incision and the scar will be larger.

After surgery, the chest will be bruised and swollen, and the person may have to wear an elastic pressure garment to reduce the swelling.

It will normally take about 6 weeks for people to return to a normal routine. Complications from surgery are rare. They include insufficient breast tissue removal, uneven chest contour, and reduced sensation of one or both nipples.

Excision may carry a risk of a blood clot forming, which may require draining.

Gynecomastia typically resolves without treatment between 6 months to 2–3 years. However, if there is an underlying condition, it may need treatment.

If the condition stems from a medication, the person may need to switch to a different drug. If the individual is using the medication for a short time, the condition will be temporary.

Treatment is rare but can include breast reduction surgery or hormone therapy to block estrogen.

Medications for the treatment of gynecomastia

Tamoxifen is a drug that blocks the action of the female hormone estrogen in the body. It is typically a treatment for breast cancer, but it can also reduce breast pain and breast enlargement symptoms in males.

Aromatase inhibitors are typical treatments for breast and ovarian cancer in post-menopausal people, but they could also prevent or treat gynecomastia.

Testosterone replacement can treat gynecomastia in older males with low testosterone levels.

Several factors can cause gynecomastia.

Gynecomastia can stem from an imbalance between the sex hormones testosterone and estrogen. Estrogen makes breast tissue grow, while testosterone stops estrogen from making breast tissue grow.

While both males and females have testosterone and estrogen, testosterone is typically higher in males and estrogen higher in females. Newborn and young boys may develop gynecomastia as their hormones fluctuate during development. However, it usually resolves on its own.

Swollen breasts can occur again in males approaching older age. Older men produce less testosterone and have higher body fat than younger men, which can increase estrogen levels.

Some males will develop the condition from herbal products or medications, such as:

Gynecomastia is not normally a serious problem.

Symptoms include swelling and tenderness in the breast gland tissue of one or both breasts. It may start as a lump or fatty tissue around a person’s nipples. In most cases, the lumps will develop unevenly.

If there is unusual and persistent swelling, pain, nipple discharge, or a combination of these, it is important for people to consult a physician.

The doctor will ask about a person’s symptoms, medical and drug history, and possibly family history. There will be a physical examination of the breast tissue, which may also extend to the genitals and abdomen.

If the cause appears to be a hormone imbalance, the doctor may suggest that the condition should resolve on its own without treatment.

If the lump is abnormally large, tender, or one-sided, the physician may order a biopsy or blood test to rule out breast cancer.

Further tests will seek to eliminate other causes, such as:

  • cyst
  • abscess or furuncle
  • benign tumor such as lipoma or hamartoma
  • mastitis, which is inflammation of breast tissue
  • hematoma, a solid swelling of clotted blood
  • metastasis, a cancer that has spread from elsewhere in the body
  • fat necrosis or a lump resulting from damage to fatty breast tissue

The doctor may also order imaging tests that include:

Gynecomastia is a condition that causes enlarged breast tissue. It can result from hormonal changes that promote breast tissue growth. Gynecomastia does not cause the accumulation of body fat and is unrelated to obesity.

A person who is overweight or with obesity will have fat around their body. This can result in enlarged breasts in men. However, this enlargement is due to fat rather than tissue growth, as in gynecomastia.

Cases of gynecomastia will typically resolve without the need for treatment. Newborns and young boys may experience symptoms decreasing over time and eventually ceasing.

In some cases, people may require treatment. This could involve liposuction or surgery. The treatments are typically safe and unrelated to long-term health risks.

Gynecomastia causes one or both breasts to grow in males due to enlarged or overdeveloped breast tissue. The condition could be due to hormonal changes or following certain medications. Symptoms will typically resolve without treatment.

Treatments are available for gynecomastia, such as liposuction. However, they are usually unnecessary in most people.