My mother had hysterectomy with ovaries removed in june 2005. She is currently 55 years old. She has frequent urge to urinate after every 30mins or so. The volume of urine is not so much though. Her sugar levels are normal, no thyroid problem. She is 71 kgs. Usg full abdomen showed normal except very mild fatty liver and post residual volume of urine at 12 cc. She has low iron and low vitamin d3 as per blood tests. Urine routine and culture also normal. What could be the reason for her frequent urge to urinate?