The reasons why your body shakes when you urinate include urethritis, cystitis, sudden drop in pressure, and drop in body temperature. 1. Urethritis: due to inflammation of the urethra, the mucous membrane of the urethra is damaged, causing a transient tingling when urinating, so the body will appear reflexive shaking phenomenon. 2. Cystitis: because of various factors lead to bladder inflammation, bladder mucous membrane erosion, bladder contraction during urination will stimulate the erosion site leading to pain, so the body may be shaking. 3. Sudden drop in pressure: when the pressure of the bladder suddenly drops after urination, the bladder muscle relaxation at this time will appear reflexive twitching phenomenon. 4. Decrease in body temperature: Since a lot of heat is discharged during urination, which leads to a drop in body temperature, the body may shake a little. Finally, if the phenomenon of body shaking while urinating cannot be relieved by oneself, please consult a doctor in time.