See a doctor to confirm the cause of the chest enlargement
Review current medications and supplements with a clinician
Get blood tests if recommended to check hormone levels and other causes
Treat any underlying condition such as obesity, liver disease, thyroid disease, or hormone imbalance
Stop using anabolic steroids, testosterone without medical supervision, and recreational drugs if applicable
Limit alcohol use
Lose excess body fat through diet and exercise if overweight
Build chest and upper-body muscle with resistance training
Consider prescription treatment if the gynecomastia is recent and persistent
Consider surgery if the tissue is long-standing, severe, painful, or does not improve with other treatment
Seek urgent medical care if there is a hard lump, nipple discharge, rapid growth, or one-sided swelling