If you have pain when urinating, you may suffer from urinary system diseases and need to go to the hospital for further examination to clarify the causes: 1. urinary tract infection, which is the most common cause, after the occurrence of urinary tract infection, the mucosa of the urethra, bladder and renal pelvis becomes congested and edematous. This is the most common cause of urinary tract infection, when the mucous membrane of the urethra, bladder and renal pelvis becomes congested and edematous, a certain painful sensation will occur during urine storage or urination, caused by urine stimulation of the mucous membrane of the lesion, further urine routine laboratory tests and urine culture tests are needed to clarify the diagnosis and use the right medication. 2. The painful urination may be accompanied by red urine or increased frequency of urination, and further ultrasound examination of the urinary system is needed to confirm the diagnosis. 3. Painful urination can also be caused by tumors of the urinary system, mostly in elderly patients, and most patients may have hematuria in addition to pain, which needs to be ruled out by ultrasound or CT examination of the urinary system.