Urethral pain after sex at the age of 15, consider urinary tract infection (such as gonorrhea urethritis, non-gonococcal urethritis), urethral injury or urethral stones and other diseases. 1. urinary tract infection: in the process of sexual life, not timely and good cleaning or there are carrying bacteria secretion through the urethral orifice into the urethra after invasion of the urethral mucosal epithelial cells after the emergence of infection, caused by urethral infection, the patient may have frequent urination, urinary urgency, urinary pain and other symptoms. If caused by gonococcal urethritis, there is pus discharge from the urethra; for non-gonococcal urethritis, there will be dilute plasma discharge or leukorrhea and other manifestations. 2. Urethral injury: it can be seen in men, if the sexual life process is too rough, it can lead to penile spongiosum injury, with pain or local hematoma and other symptoms. 3. Urethral stones: stones mostly come from kidney and bladder, the typical symptoms are difficulty in urination, dribbling urination, also can be accompanied by urinary pain. Urethral pain after sex or other uncomfortable symptoms should be timely medical care, urine routine and other related examinations, treatment as prescribed by the doctor, it is recommended to avoid early sex and unclean sex.