Masturbation does not cause gynecomastia. There are many theories about what causes it, but there is no definitive answer. Many healthy, athletic males, including athletes with low body fat can have gynecomastia. Having gynecomastia is not your fault. Many males, including many teens suffer with gynecomastia. For some teens, the gynecomastia will go away in time. For others, it won't go away. I would encourage teens to discuss this with their parents, and I would encourage parents to discuss this with their teens. A male does not have to live with gynecomastia. Surgery, when expertly performed can leave the chest looking and feeling smooth and even. Ideally, scars will ultimately fade to barely perceptible.