Kidneys usually do not have cramps, but may have twitch-like pain, which may be caused by transient nerve reflex, kidney stone, urine reflux and other factors. 1. Transient nerve reflexes: some people experience twitching pain in the kidney area due to nerve reflexes during urination, but it will disappear soon, which is considered to be caused by physiological factors. There is no need to do special treatment. 2. Kidney stones: there are small stones in the kidneys and ureters, and when urinating, the stones may move to induce discomfort in the kidney area, which may be accompanied by pain in the lower back, which can be clarified by ultrasound examination. 3. Urine reflux: some patients have damage to the ureteral anti-reflux mechanism, when urinating, the urine in the bladder will reflux into the ureter and renal pelvis, thus causing kidney and ureteral spasm, and generally return to normal after the end of urination. In general, the pain in the kidney area during urination is relatively rare, if the above situation needs to go to the hospital in time to check the cause of the disease and carry out targeted treatment.