Suddenly afraid to urinate, cramping pain may be related to cystitis, urethritis, neurological disorders and other causes. 1. Cystitis: It can be caused by bacterial infection. At the same time, when the surface of cancer in the bladder becomes necrotic, it can also lead to cystitis. The bladder irritation symptoms of frequent urination, urgency, painful urination and, in severe cases, hematuria of the naked eye can occur. 2. Urethritis: when the urethra is infected or inflamed and irritated, it can lead to uncontrolled contraction of the longitudinal and circumferential muscles of the urethra, which is called spasm of urethral musculature. At the same time, the inflammation makes the mucous membrane damaged, so that the nerve is directly stimulated by the urine, thus causing spasmodic pain. 2. Neurological disorders: for example, when there is an injury to the pubic area, perineal area nerve roots or spinal cord, it can lead to inflammation and make the local muscles twitch and spasm. This leads to cramp-like pain during urination. When there is a sudden dare not urinate, cramping pain, it is recommended to go to the hospital for examination, clear causes, under the guidance of the doctor for targeted treatment.