what causes gyno

Gynecomastia, or “gyno,” is usually caused by a hormone imbalance where estrogen’s effect is higher than testosterone’s, or testosterone is lower than normal. It can also be triggered by certain medicines, medical conditions, and substances.

Common causes

• Normal hormone shifts during puberty or aging.

• Medications that affect hormones, including some heart drugs, ulcer medicines, anti-anxiety medicines, steroids, and HIV/AIDS medicines.

• Substances such as anabolic steroids, alcohol, marijuana, heroin, and methamphetamines.

• Medical conditions like liver disease, kidney failure, hyperthyroidism, hypogonadism, obesity, and certain tumors of the testes, adrenal glands, pituitary gland, or prostate.

• Poor nutrition or starvation , which can lower testosterone.

When to get checked

If breast enlargement is new, painful, one-sided, hard, or comes with nipple discharge or a testicular lump, it should be evaluated by a clinician. Those features can help distinguish true gynecomastia from other causes of chest swelling or more serious conditions.

Simple takeaway

Most cases come down to some mix of too much estrogen effect, too little testosterone effect, or both.

TL;DR: Gyno is most often from a hormone imbalance, but meds, steroids, alcohol/drugs, obesity, liver/kidney/thyroid problems, and some tumors can also cause it.