Hi, Thanks for writing in to us. Pyelonephritis is a condition where there is infection in the kidney. This is a moderate infection and requires a strong antibiotic like ciprofloxacin for it to be cured. If you had to be in hospital then your doctors have stabilized your condition and then sent you home. It usually takes 15 days to feel normal. However it can take slightly longer in elderly people like you because of other conditions like hypertension and diabetes should you have them. Please drink adequate amount of water and visit washrooms regularly. You should not hold your urine for long duration because this can cause recurrent infection. Feeling crummy during the recovery phase is felt by many patients and this can be there for few days. In almost every patient the recovery is complete in one month. Please do not worry.