Ureteral Stricture: A Narrowed Urine Pipe and How It Is Fixed

Last updated September 4, 2026.

A ureteral stricture is a narrowing of the ureter, the tube that carries urine from each kidney down to the bladder. Urine drains poorly through the narrowed segment, pressure builds upstream, and the kidney on that side can be damaged over time if the narrowing is not relieved. The good news is that the pipe can be protected and repaired, and most kidneys recover well once the drainage is restored.

How a ureter narrows

Most strictures are scars. Kidney stones, surgery near the ureter, radiation treatment, and endometriosis are the common causes, and occasionally a stricture is present from birth where the ureter joins the kidney. The scar shrinks the passage slowly, which is why the problem often surfaces months or years after the original injury.

A swollen kidney above a narrowed ureter is urine backing up, and the fix protects the kidney. Fever with flank pain on that side is an emergency, same day.

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How it shows up

Dull flank pain on one side, especially after drinking a lot of fluid, is the classic symptom. Recurrent urine infections on one side, blood in the urine, or a kidney that shows swelling on a scan done for something else are the other common ways it is found. Sometimes there are no symptoms at all until the kidney has already lost function, which is why an unexplained swollen kidney on a scan always gets investigated rather than watched.

How it is fixed

The first job is protecting the kidney, which usually means a temporary stent, a thin tube threaded up the ureter that holds the passage open, or occasionally a nephrostomy, a small drain placed through the back into the kidney. The definitive repair depends on where and how long the stricture is. Short narrowings can sometimes be opened from inside with a scope. Longer or recurrent ones are repaired surgically by cutting out the scarred segment and rejoining the healthy ends, usually with keyhole or robotic surgery. Follow-up scans continue for a couple of years because a repaired ureter can narrow again, and catching that early protects the kidney.

The kidney is the priority. Every decision in stricture care is about keeping that kidney draining and healthy. The plumbing repairs serve that one goal.
Report fever with flank pain urgently. A blocked ureter plus infection is an emergency. High temperature, shaking chills, and pain on the stricture side means the emergency department the same day.
Keep the follow-up scans. Recurrence is usually silent, and the scans are how it is caught early.

If you are weighing the risks and benefits of any procedure or medicine mentioned here, our overview of how treatments are tested and monitored for safety explains what those conversations are built on.

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I am 52 and had kidney stones two years ago. Now a scan shows my left ureter is narrowed and the kidney above it is swollen. They want to do surgery to cut out the narrowed part. Is this really necessary, and what happens to my kidney?

The swelling above the narrowing is the answer to your first question. That swelling, called hydronephrosis, is urine backing up because the pipe is scarred shut, and left alone it quietly damages the kidney on that side. The surgery is not for the scan finding; it is for the kidney. The good news is real: kidneys tolerate a lot, and function that is still present usually holds or improves once the drainage is restored, especially when the blockage is dealt with before severe damage sets in. The operation they are describing, cutting out the scarred segment and rejoining the healthy ends, is the standard durable repair for a stricture like yours, usually done with keyhole or robotic techniques, with a stent left in place for a few weeks while it heals. The alternative to surgery is not no treatment; it is a long-term stent changed every few months, which suits some people but brings infections and encrustation with it. Ask your urologist what your kidney function tests and the drainage scan show, because those numbers tell you how much kidney there is to protect.

Thanks for giving me all this information. A narrowing that surfaced two years after stones is the classic story, and the plan your team has laid out, protect the kidney, then repair the pipe, is the right sequence. Your questions for the urologist: what do my kidney function and drainage scans show now, what repair are you planning and why, how long will the stent stay, and what is the follow-up scan schedule afterward. Keep the follow-up scans even when you feel fine, because a recurrence is usually silent. This is a fixable problem, and fixing it is what protects the kidney.

Care note

52M post-stone stricture, pre-ureteroplasty. Two questions bundled: is surgery necessary, and what happens to the kidney. Answer pairs the why (hydronephrosis quietly damages) with the honest upside (function usually holds once drainage is restored), and names the actual alternative (long-term stent) so surgery is a choice against something real, not against doing nothing.

Sources are the weak point here: MedlinePlus ureteral disorders is an umbrella page (flag) and UCSF urology is an academic center page (flag); no NHS or dedicated MedlinePlus stricture page exists. Kept fever with flank pain as the emergency line because a blocked and infected kidney is the one scenario that kills kidneys fast. No chains, banned adverbs absent.

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Illustrative example, not a real member's messages.

Common questions

What causes a ureteral stricture?

Most are scars from kidney stones, surgery near the ureter, radiation treatment, or endometriosis. Some are present from birth where the ureter joins the kidney. The narrowing develops slowly, often months or years after the original injury.

Can a stricture damage my kidney?

Yes. Urine backs up above the narrowing and the resulting pressure can damage the kidney over time, sometimes without symptoms. That is why an unexplained swollen kidney on a scan is always investigated, and why strictures are repaired rather than simply watched.

Is surgery always needed?

Not always. Some people are managed with a stent changed regularly, and short strictures can sometimes be opened from inside with a scope. Longer or recurrent strictures are repaired by removing the scarred segment and rejoining the healthy ends, usually with keyhole or robotic surgery.

What is a ureteral stent like to live with?

A stent is a thin tube inside the ureter holding it open. Common effects are more frequent urination, some discomfort in the flank or bladder, and a trace of blood in the urine. It is temporary, and it comes out in a quick procedure when its job is done.

Can the stricture come back after repair?

It can, which is why follow-up scans continue for a couple of years after repair. Recurrence is usually silent, and catching it early on a scan protects the kidney before damage builds again.

What symptoms mean I should seek urgent care?

Fever or shaking chills with pain on the side of the stricture means a blocked and possibly infected kidney, which is an emergency. New severe flank pain, vomiting with the pain, or being unable to pass urine also mean urgent assessment.

Sources

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