What causes it
Anything obstructing the flow of urine anywhere from the kidney to the urethra, and occasionally reflux of urine back up towards the kidney.
- A stone in the ureter — the commonest cause in adults
- PUJ obstruction, often present since childhood
- Prostate enlargement causing back pressure from below
- Urethral stricture or bladder neck obstruction
- Tumours of the bladder, ureter or nearby pelvic organs
- Pregnancy, which causes mild physiological dilation
Why it should not be watched indefinitely
A kidney under sustained back pressure loses function progressively, and the loss is permanent. The warning sign is that this is often painless — long-standing obstruction from a stricture or PUJ obstruction can destroy a kidney without any symptom other than a scan finding.
Hydronephrosis with fever means an obstructed, infected kidney. This needs drainage the same day, not an outpatient appointment next week.
Treatment
Urgent drainage where infection or acute deterioration is present, with a DJ stent or a percutaneous nephrostomy. Then a renogram measures how much function that kidney still has, and the underlying cause is treated definitively — stone clearance, pyeloplasty, prostate surgery or stricture repair as appropriate. A kidney with negligible remaining function may occasionally be better removed than preserved.
Hydronephrosis Treatment — common questions
Is hydronephrosis dangerous?
It depends on cause, degree and duration. Short-lived obstruction usually recovers fully; prolonged obstruction causes permanent loss of function.
Can hydronephrosis be treated with medicine?
No. The blockage has to be relieved. Medication has a role only in treating associated infection or pain.
Does mild hydronephrosis in pregnancy need treatment?
Usually not — it is a normal physiological finding. It needs treatment only if there is a stone, pain or infection.
Will kidney function return after the blockage is relieved?
Often partially or fully, depending on how long the obstruction was present. A renogram measures what has recovered.
Reviewed by Dr. Kinjal Banerjee, MBBS, MS (General Surgery), DNB (Urology) — Urologist, Renal Transplant & Robotic Surgeon, Faridabad. This page explains hydronephrosis treatment in general terms; your own treatment plan depends on your reports and examination.