Is gynecomastia caused by an imbalance of hormones?

Sometimes: Sometimes caused by drugs- legal & otherwise- or often no known cause.

Sometimes (rarely).: Most gynecomastia is idiopathic (meaning no medical cause--just happens), usually from puberty. Usually resolves, sometimes does not. Some medications, hormones, external estrogen-like compounds, and even marijuana use, and rarely, things like testicular tumors, can all cause gynecomastia. Being overweight worsens the issue, and plastic surgery is usually the only/best treatment for this. See a md.

Yes: The diagnoses of this requires a proper evaluation by your physician.

Often...: Gynecomastia comes from the greek meaning "gyne" meaning woman and  "mastos"  meaning breasts.  it refers to abnormal development of large mammary glands in males. Although there may be many “causes”, most cases are idiopathic (no specific cause). The use of certain medications, drugs, organ dysfunction (kidney or liver), hormonal imbalances (directly or indirectly) etc. May also be causative.

Gynecomastia: Enlarged male breasts can come from a number of different causes. Before any treatment can be done, you must first have a complete physical exam and may need bloodwork to rule out hormonal issues. There are a number of medications that can also cause gynecomastia. Once all medical reasons are ruled out, one may consider treatment. You should seek a consultation with a plastic surgeon.