Yes. A ureteric stricture can damage the kidney because it narrows the tube that drains urine from the kidney to the bladder. If the blockage is significant, urine backs up and the kidney becomes dilated (hydronephrosis). Persistent obstruction can reduce kidney function, and infection behind an obstructed ureter can become an emergency. Some strictures cause flank pain, fever or recurrent infection, but others are surprisingly silent and are discovered only on ultrasound, CT or a renal function scan. The urgency depends on infection, degree of obstruction, kidney function and whether the opposite kidney is healthy.

What is a ureteric stricture?

The ureters are two narrow tubes carrying urine from the kidneys to the bladder. A ureteric stricture is scar narrowing of one of these tubes. It may follow ureteroscopy or stone surgery, previous abdominal/pelvic surgery, radiation, inflammation, trauma, urinary leakage or a previous ureteric repair. The narrowing can be short or long and can occur close to the kidney, in the mid ureter or near the bladder.

How does it harm the kidney?

The kidney continues to make urine even when drainage is restricted. Pressure builds above the narrowing, dilating the collecting system. If severe obstruction persists, the affected kidney can gradually lose functional tissue. The speed of damage varies: complete obstruction is more urgent than a partial narrowing, and an infected obstructed system can become dangerous very quickly.

Symptoms to look for

• Flank or loin pain, sometimes worse after drinking large amounts of fluid.
• Repeated fever or urinary infection.
• Nausea or vomiting during episodes of obstruction.
• Blood in urine in some patients.
• Reduced kidney function on blood tests.
• Hydronephrosis found incidentally on ultrasound or CT.
• No symptoms at all despite significant obstruction in some cases.

Can a dangerous ureteric stricture be painless?

Yes. Pain is an unreliable measure of how much the kidney is being obstructed. A slowly developing narrowing can be almost silent while hydronephrosis and loss of differential kidney function progress. This is why imaging and, when needed, functional renal scanning matter more than symptoms alone.

How do doctors know whether the kidney is truly obstructed?

Ultrasound

Ultrasound is useful for detecting hydronephrosis but does not always show why the ureter is blocked or how much kidney function is at risk.

CT urography

CT with delayed images can show the level of narrowing, hydronephrosis, stones, surrounding anatomy and sometimes urinary leakage. It is often central to planning.

Retrograde or antegrade pyelography

Contrast is placed through the bladder or through a nephrostomy to outline the ureter directly. This is useful when the exact stricture length is unclear or when a stent cannot pass.

Nuclear renal scan

A diuretic renogram such as MAG3/DTPA can estimate how much each kidney contributes to total function and whether drainage is obstructed. This matters when deciding whether reconstruction is worthwhile in a poorly functioning kidney.

Can kidney function recover after treatment?

Sometimes. Recovery depends on how complete the obstruction was, how long it lasted, whether infection occurred and the baseline health of the kidney. A kidney with preserved parenchyma may recover well after drainage and reconstruction. Severe chronic obstruction can cause irreversible loss, which is why persistent hydronephrosis should not be ignored.

How is the ureteric stricture treated?

A short selected narrowing may be treated endoscopically with dilatation or incision and temporary stenting. Dense, long, recurrent or completely blocked strictures are more likely to need reconstruction. Options include ureteroureterostomy, ureteric reimplantation, psoas hitch, Boari flap, buccal mucosa graft ureteroplasty, ileal ureter or, rarely, renal autotransplantation. The operation is chosen according to site, length and tissue quality.

What to bring for consultation

• CT urography/CT KUB images, not only the report.
• Ultrasound reports showing hydronephrosis over time.
• Renal scan (MAG3/DTPA) if performed.
• Creatinine/eGFR and urine culture.
• Previous ureteroscopy, stone surgery, gynaecological/colorectal or pelvic surgery records.
• Stent/nephrostomy dates and prior attempts at dilatation or reconstruction.

Partial versus complete obstruction

A partial stricture may allow enough drainage to preserve function for a long time, while a complete obstruction can threaten the kidney much faster. The degree of hydronephrosis on one scan does not fully describe the functional effect. Renal scans assess drainage dynamically and help distinguish a dilated but draining system from one in which urine is truly held back by the stricture.

Why a solitary kidney changes urgency

If only one kidney functions well, obstruction of that ureter can affect the patient’s overall kidney function rather than only one side. Rising creatinine, reduced urine output or infection in a solitary kidney deserves urgent assessment. Temporary drainage with a stent or nephrostomy is often prioritised before any discussion of definitive reconstruction.

What if the affected kidney contributes very little function?

A very poorly functioning kidney creates a different decision. The urologist considers the remaining cortical tissue, symptoms, infection, renal scan contribution and whether function improves after drainage. Major reconstruction may still be worthwhile in selected kidneys with recoverable function, while nephrectomy may be more appropriate when the kidney is irreversibly damaged and causing recurrent infection or pain.

FAQs

Related reading

• Ureteric Stent: Why It Is Placed
• What If a Ureteric Stent Does Not Fix the Blockage?
• How Is the Type of Ureteric Reconstruction Decided?
• Recovery After Ureteric Reconstruction
• Hydronephrosis: Causes and Treatment
• Can Urethral Stricture Damage the Bladder or Kidneys?
• Urologist in Latur

References

• European Association of Urology. EAU Guidelines on Urological Trauma: Ureteral Trauma, 2026 https://uroweb.org/guidelines/urological-trauma/chapter/urogenital-trauma-guidelines
• Bourillon A, Peyronnet B, McGuire BB, et al. Ureteral stricture: current treatment algorithm and key surgical principles in the robotic upper urinary tract reconstruction era. World J Urol. 2026;44(1):102. doi:10.1007/s00345-025-06181-4.
• Fuller TW, Daily AM, Buckley JC. Robotic Ureteral Reconstruction. Urol Clin North Am. 2022;49(3):495-505. doi:10.1016/j.ucl.2022.05.002.