What causes gynecomastia?
Gynecomastia is usually caused by changes in hormones at puberty or as part of aging. Gynecomastia may be caused by changes in the balance of 2 hormones: estrogen and testosterone. Sometimes, gynecomastia may be caused by prescription drugs (cardiac, high blood pressure meds, etc.), over-the-counter medicines (allergy, asthma meds, etc.), illegal drugs, tumors or disease (as liver problems).