Pain when urinating, then the possible causes: 1, urinary tract infection, infection due to bacterial invasion of the urinary epithelium, and epithelial local damage, and then the epithelium of the erosion, congestion, edema and other changes. Then there will be pain during urination, burning and stinging pain in the urethra, frequent urination, urinary urgency and suprapubic pain or lumbago and other symptoms. Routine urine examination and culture test can confirm the diagnosis, need to carry out anti-infection treatment. 2, urinary stones can also appear pain, because the stone stimulation of local mucous membrane and produce local damage, can also appear local obstruction and lead to mild hydronephrosis. This can occur when the pain of urination or back pain and other symptoms, the need for extracorporeal shock wave lithotripsy treatment, the pain can be relieved or disappear. 3, urinary tract trauma can also occur urinary pain, especially common in men. Because the male penis is hanging, it is easy to be hit by external factors or extrusion, contusion, etc., resulting in pain and bleeding in the urethra. It is usually accompanied by redness and swelling of the glans and redness and swelling of the urethra, and there is a clear history of trauma at the onset.