Gynecomastia is excess breast tissue growth in the male chest, which can cause tenderness, swelling, and pain. Some men may have false gynecomastia (also known as pseudogynecomastia) so Dr. Katzen encourages patients to lose weight with a healthy diet and exercise before seeking treatment for gynecomastia. If you still have enlarged breasts even at a healthy weight, Dr. Katzen can perform an examination and tests to diagnosis gynecomastia. This may include blood tests, a mammogram, or a biopsy to rule out other conditions, like breast cancer and mastitis (infection of the breast tissue).