I have a 5mm stone that is stuck in the ureter, just outside the bladder. it has caused mild hydronephrosis and hydro-ureter. i have no pain at all, just a slight "awareness" in my lower back. 3 questions. 1. how swiftly must this be addressed" days?

Stone: I would suggest you see a urologist as soon as possible. Any hydronephrosis is not good - it may lead to infection, kidney dysfunction. Size of stone is immaterial - its the effects it is causing that matters.

Quickly: The findings you describe indicate there is impairment to your kidney's output and "back pressure" on the kidney. This can cause permanent damage to the kidney with loss of function if ignored. I would seek aggressive treatment like a stent to bypass the blockage or lithotripsy to breakup the stone rather than watchful waiting if it were my kidney.

No rush, may pass: Most 5 mm ureteral stones pass spontaneously. Your symptoms are mild and you have had either a ct or a renal ultrasound & are under care so there is no immediate need for intervention. Urine should be filtered in case stone is passed. Studies can be repeated in 2 weeks, or sooner if symptoms increase, risk of renal damage is minimal. Stone can be removed later as needed.Ureter.