It could be due to reasons like urinary tract infection, small stone in the ureter close to bladder and urinary tract obstruction. Get a urine culture and sensitivity test, uroflowmetry, urine complete analysis and ultrasound examination of abdomen and pelvis with post void residual urine assessment. If the investigations are negative, you would have overactive bladder. Take Tab. Mirago 50mg once a day for 5 days, see the response. Upload your investigations in an online consultation, would be helpful to give a best possible solution.