The urodynamic examination requires maximum holding of urine during the examination, holding the urine and then urinating, observing and recording the whole process of urination through the instrument, and evaluating whether there is any abnormality in each index. Urodynamic examination is to examine the power, pressure, flow and sphincter function status of the urinary tract system, analyze and judge whether the bladder function is normal, whether the urethra is smooth, etc., and then treat according to the cause of the disease. Lower urinary tract urodynamic examination mainly includes measuring the pressure difference between bladder and rectum, urethral sphincter closure pressure, urine flow rate, residual urine, etc. Upper urinary tract urodynamic examination mainly measures the pressure difference between renal pelvis and bladder. Among them, the maximum bladder capacity index that requires the patient to maximally hold urine. If you want to undergo urodynamic examination, please visit a regular hospital and follow the doctor’s instructions.