The urinary tract involves the ureter, urinary bladder, and the urethra. The muscle that lines the urinary tract is the smooth muscle. Muscle spasm of the urinary tract occurs due to the abnormal involuntary contraction or squeezing action of the muscles leading to pain. Muscles spasms of the ureter are commonly caused by renal or ureteric calculi leading to obstruction in the flow of the urine. When muscle spasm occurs in this situation, it often leads to colicky pain. Muscle spasm of the bladder is caused by bladder calculi, infections or even surgery. This condition often leads to urge incontinence. Other risk factors or causes that may lead to muscle spasm of the urinary tract are diabetes, enlarged prostate, urinary tract infections, stroke, spinal cord injury, bladder catheterization, recent pelvic surgery, and certain medications. Muscle spasm of the urinary tract needs medical attention and has to be treated.