Hello, Pain in the upper side of the penis after masturbation (shaft and head) can occur due to rough or prolonged masturbation that causes trauma or internal injury. Wear soft cotton clothes. Make sure that your clothes do not rub against the penile shaft. When tissue below your penis skin that helps you get an erection is torn, it will cause pain. For relief take acetaminophen or any other analgesic, one stat when needed to get relieve from pain and inflammation. Take medicine after you have taken food. It can also happen when the corpus cavernosa tears. Be gentle with yourself. Masturbation causes increased blood supply and congestion in the penis and the prostate. Do not masturbate in excess for a prolonged period of time and avoid rough masturbation as prostatic congestion causes more prostatic secretions and pain in the penis. The pain referred to the tip of the penis is usually from the prostatic site. I do not think you need to worry. However, get clinically examined by a Urologist to detect or rule out underlying medical conditions like Peyronie’s disease and UTI. You will be treated accordingly. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician