What Is Gynecomastia? - Causes, Symptoms & Treatment

Instructor: Marisela Duque

Marisela teaches nursing courses at the college level. She also works as a unit educator, teaching experienced nurses about changes in nursing practice.

After completing this lesson, you will be able to describe gynecomastia, including its causes, symptoms, and treatment options. A short quiz follows the lesson so that you can test your new knowledge.


Hi, my name is John, and I'm 14 years old. My school has yearly tryouts for the basketball team, but I am too scared to go. If I make the team, then everyone will know that I'm different. You see, I have a large chest. For some reason, my chest started to grow when I was 11, and it hasn't gone away. Most of my friends don't know, but the kids that do notice tease me about needing a bra. When I finally talked to my dad about it, he took me to a doctor who said I have gynecomastia, which is a really long word for large breast tissue in boys or men. Keep reading to find out more.

Gynecomastia Defined

Gynecomastia is a medical term that describes the overgrowth of breast tissue in men or boys. This can occur at any age and affect one or both breasts, sometimes unevenly. This condition is common during puberty and sometimes resolves on its own. It is a benign condition, but it can cause emotional turmoil and negatively affect self-esteem.


The most common cause of gynecomastia is a hormonal imbalance. The hormones to blame are estrogen (female hormone) and testosterone (male hormone). While testosterone is considered the masculinizing hormone, all men produce both testosterone and estrogen throughout their lifetime. There are times when the scale is tipped, and the estrogen and testosterone balance goes a little haywire. This happens in newborns, during puberty (as in John's case), and in old age.

Newborns experience breast growth because they are exposed to high estrogen levels while they are in the womb. According to the Mayo Clinic (2015), more than 50% of boys are born with enlarged breast buds because of this. But there is no cause for alarm; this usually goes away before a baby reaches six months.

Puberty is a time of intense hormone fluctuations, which is apparent if you ever talk to any preteen. Fortunately, gynecomastia that occurs during this time usually goes away within six months to two years. In older men (over 50), the hormonal changes that occur during aging, especially in overweight men, causes this condition, but it generally sticks around unless they receive treatment.

While the above are all naturally-occurring cases of gynecomastia, there are some other possible causes. Some medications, such as hormone treatment for an enlarged prostate or prostate cancer, chemotherapy, HIV medication, antibiotics, antidepressants, and some herbal remedies (lavender, tea tree oil, and dong quai) may be responsible. People who abuse alcohol and drugs (heroin, marijuana, methadone, and amphetamines) are also at risk for developing breast enlargement. Some health conditions can also cause gynecomastia. These include chronic liver disease, kidney failure, low testosterone levels, genetic defects, overactive thyroid, and tumors.


The main symptom of gynecomastia is overgrowth of breast gland tissue in boys or men. Some people also experience breast pain or tenderness.

Treatment Options

As mentioned earlier, most cases of gynecomastia resolve in their own in time. There are treatments available if it does not go away or if the person experiences severe pain or embarrassment. The treatment recommended for these cases include medication and surgery.

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