It is recommended to go to the hospital for further examination to clarify the possible causes: 1, acute urethritis or cystitis, which can appear frequent and painful urination, accompanied by a sense of incomplete urination or lumbar pain, some patients can appear urethral discharge, etc., often due to acute infections, need acute urine routine laboratory tests to confirm the diagnosis. 2, after unclean sexual contact can appear suddenly frequent and painful urination. The majority of them are suffering from sexually transmitted diseases, such as gonococcal infection, mycoplasma infection, chlamydia infection, etc., and generally have a history of unclean sexual contact, it is recommended to go to the hospital to carry out the relevant scientific examination of sexually transmitted diseases to confirm the diagnosis. 3, if there are urinary stones in the body, such as kidney stones, ureteral stones, the location of the stones has changed, and the discharge into the bladder or urethra can suddenly cause frequent and painful urination, especially stones stuck in the urethra can appear as persistent pain in the urethra, and the pain is aggravated during urination or accompanied by bleeding, etc.