Causes of a Swollen Male Breast

The most common cause of swollen males breasts is gynecomastia, which is usually caused by hormonal changes. Weight gain and certain medications can also cause male breast growth.

Men generally have far less breast tissue than women and consequently have a lower incidence of breast-related health concerns, according to Harvard Medical School 4. However, some conditions may cause swelling or breast pain in men.

Causes of Gynecomastia

Gynecomastia is a condition that causes enlargement and swelling of breast tissue in males, according to the Cleveland Clinic 12. Gynecomastia typically results from a hormonal imbalance but it can have the following causes as well.

Hormonal changes 3

Both men and women have some amount of the hormones estrogen and testosterone. But males typically have more testosterone — it's one of the hormones that controls muscle mass and body hair, per the Cleveland Clinic. But if males have higher levels of estrogen (the hormone that controls breast growth in females), or lower levels of testosterone, it can cause breast growth 3.

Read more: Estrogenic Foods to Avoid

Gynecomastia typically affects males during periods of normal hormonal changes, according to the Mayo Clinic 1. Males can experience breast growth in the first few weeks after birth, during puberty and in later life (between the ages 50-70).

Gynecomastia isn't a serious problem, per the Mayo Clinic 1. But it can cause discomfort including swollen breast tissue and breast tenderness. Usually, this pain will go away on its own. But if pain doesn't go away, if it increases or if you see fluid discharge from the nipples, consult a doctor.

Weight Changes 3

Roshni Rao, MD, chief of the Breast Surgery Program at Columbia University Medical Center, spoke with about some of the other causes of gynecomastia. "Many times, [gynecomastia] is related to weight gain," says Dr. Rao.

It's understandable why weight gain can cause breast growth. But it may surprise you to learn that a lack of nutrition can also cause gynecomastia, per the Mayo Clinic 1. Inadequate food intake causes testosterone levels to drop while estrogen levels stay the same. A greater estrogen-to-testosterone ratio can cause breast growth.

Read more: What Is the Average Adult Male Height and Weight?

Medical Conditions

Dr. Rao says that gynecomastia can also be caused by certain medical conditions, like liver disease. Additionally, conditions that interfere with testosterone levels like hypogonadism or tumors in the testicles or adrenal glands can also cause male breast growth, per the Cleveland Clinic 2.

Note that these conditions will almost certainly cause other symptoms besides swollen breast tissue. Gynecomastia by itself is not a sign of these conditions.


Some medications and substances can cause breast growth. These include mental health medications, antibiotics and medications used to treat ulcers and cancer, per the Mayo Clinic. Marijuana, anabolic steroids (sometimes used for bodybuilding) and illicit drugs like heroin can cause also male breast swelling.

Read more: How to Get Rid of Man Boobs Without Going to the Gym

Rare Breast Infection

Breast infections in men are rare, according to a case report published in April 2016 in the Journal of Clinical & Diagnostic Research 5. Breast infections (mastitis) are much for common for women who are breastfeeding. However, if bacteria enter the male breast (likely due to injury or trauma to the breast), it can cause an infection and swelling. Mastitis is generally cleared up with antibiotics.

Inflammatory Breast Cancer

Breast cancer in men is very rare 678. According to, less than 1 percent of breast cancer cases occur in men 78. It may surprise you that men can get breast cancer at all 7. But all humans have breast tissue. Because women have more breast tissue — and higher estrogen levels — they are significantly more at risk. However, in very rare cases, a type of breast cancer called inflammatory breast cancer (IBC) can cause male breast growth 68.

This type of cancer is considered to be aggressive according to the American Cancer Society 678. The signs and symptoms include breast swelling, purple or red colored skin and dimpling or thickening of the skin of the breast 68. IBC grows and spreads very quickly so if you experience these symptoms, see a doctor right away. Note that even if you do have these symptoms, it does not mean that you have breast cancer. The symptoms of IBC and a breast infection are very similar so it's important to see a doctor promptly for a full evaluation.

Read more: 10 Common Causes of Lower Left Abdominal Pain in Men