A urethral stricture is a narrowing of the urethra, the tube that carries urine from your bladder out of your body. It happens when scar tissue builds up in or around the urethral wall, partially or fully blocking urine flow. The condition predominantly affects men and can develop at any point along the urethra, with symptoms ranging from a weak stream to a complete inability to urinate.
How Scar Tissue Narrows the Urethra
The narrowing starts with an injury to the urethral lining. When tissue is damaged, the body launches an inflammatory repair process. Immune cells flood the area and release chemical signals that cause scar-forming cells called fibroblasts to multiply rapidly. These fibroblasts produce collagen, the structural protein found in scar tissue, and deposit it in the urethral wall.
In normal healing, this process eventually stops. In urethral stricture, it doesn’t. The inflammation becomes chronic, and collagen keeps accumulating. The scar tissue that forms contains a higher ratio of rigid collagen types compared to healthy urethral tissue, which is why the affected area loses its natural elasticity. Over time, the channel narrows enough to obstruct urine flow. Because the underlying process is ongoing inflammation, strictures can worsen gradually and tend to recur even after treatment.
What Causes a Stricture
In developed countries, the two leading causes are iatrogenic injury (damage from medical procedures) and idiopathic causes (no identifiable origin), each accounting for roughly 32% of cases. Medical procedures that involve instruments passing through the urethra, such as catheter placement, cystoscopy, or prostate surgery, can injure the lining and trigger scarring.
Trauma accounts for about 10% to 36% of cases depending on the population studied, with higher rates in regions where pelvic fractures from accidents are more common. Straddle injuries, where force is applied to the area between the legs (falling on a bicycle crossbar, for example), are a classic cause.
Inflammatory conditions, including a skin disease called lichen sclerosus, make up about 27% of cases. Historically, sexually transmitted infections like gonorrhea were the most common cause. Better diagnosis and treatment of STIs have made infection-related strictures relatively rare in developed countries, though they remain significant in other parts of the world.
Common Symptoms
The hallmark symptom is a weak or slow urine stream. You may notice you need to strain to urinate, or that your stream sprays or splits. Other common signs include:
- Frequent urination, including feeling the need to go again shortly after finishing
- Urgency, a sudden, hard-to-control need to urinate
- Pain or burning during urination
- Recurrent urinary tract infections or prostate inflammation
- Incomplete emptying, the sensation that your bladder isn’t fully empty
Symptoms typically develop gradually as the stricture worsens. In severe cases, you may suddenly become unable to urinate at all, a condition called acute urinary retention that requires emergency treatment.
What Happens If It Goes Untreated
Left alone, a stricture forces the bladder to work harder to push urine through the narrowed passage. Over months or years, this extra strain can thicken and weaken the bladder wall, reducing its ability to empty properly. Chronic incomplete emptying creates a pool of stagnant urine, which raises the risk of recurrent urinary tract infections and bladder stones.
In the most serious cases, the backup of urine can travel upward to the kidneys, causing a condition called hydronephrosis (swelling of the kidneys due to trapped urine). Prolonged hydronephrosis can permanently damage kidney function. Long-standing strictures have also been linked to prostate inflammation and, in rare cases, sexual dysfunction.
How It’s Diagnosed
Diagnosis starts with a urine flow test, which measures how fast urine exits your body. A significantly reduced flow rate raises suspicion of a stricture, but imaging is needed to confirm it.
The gold standard is a retrograde urethrogram (RUG), an X-ray taken while contrast dye is gently injected into the urethra. This shows the exact location, length, and severity of the narrowing, all of which determine the best treatment approach. It’s sometimes combined with a voiding study, where you urinate during imaging so the entire urethra can be visualized.
Ultrasound of the urethra is another option that can map the stricture’s location and length without radiation. A urethroscope, a thin camera inserted into the urethra, lets a urologist see the narrowing directly, though it can only evaluate the area up to the blockage and not beyond it. Most treatment planning relies on knowing the stricture’s length and position, so imaging with RUG or ultrasound is typically performed before any procedure.
Treatment Options and Success Rates
Treatment depends on the stricture’s length, location, and whether it has been treated before. The three main approaches are dilation, internal incision, and surgical reconstruction.
Dilation and Internal Incision
These are the least invasive options. Dilation involves stretching the narrowed area with progressively larger instruments or a balloon catheter. Internal incision (called direct visual internal urethrotomy, or DVIU) uses a small blade or laser to cut through the scar tissue from inside the urethra. Both are outpatient procedures with quick recovery.
The catch is durability. Reported success rates range widely, from 32% to 96% for internal incision and 35% to 84% for dilation. For recurrent strictures that have already failed surgical reconstruction, the picture is bleaker: one study found that internal incision had a 95% recurrence rate within three years, with a median time to recurrence of just 99 days. Balloon dilation fared somewhat better in that setting, with a 69% recurrence rate and a median time to recurrence of about a year. These procedures work best for short, first-time strictures and become less effective each time they’re repeated.
Urethroplasty (Surgical Reconstruction)
Urethroplasty is the most durable treatment, with a reported success rate of about 96%. It’s an open surgery performed under anesthesia, where the scarred segment is either removed and the healthy ends reconnected, or the narrowed area is widened using a graft (often taken from the inner cheek or skin). The approach depends on how long the stricture is and where it sits in the urethra.
Recovery is more involved than with dilation or incision. You’ll go home with a catheter, which is typically removed after 8 to 10 days in uncomplicated cases. Some surgeons previously kept catheters in for two weeks, but research has shown shorter durations are equally safe. Full return to normal activities, including exercise and sexual activity, generally takes several weeks. The tradeoff for this longer recovery is a significantly lower chance of the stricture coming back.
Why Strictures Come Back
Recurrence is the central challenge of treating urethral strictures. Dilation and incision address the narrowing but don’t remove the underlying scar tissue, so the same inflammatory and scarring process can restart. Each treatment also creates a new wound in the urethra, which can itself scar. This is why repeat dilations tend to produce diminishing returns.
Urethroplasty has a much lower recurrence rate because it physically removes or bypasses the scarred segment. Even so, some patients do develop new scar tissue at the surgical site. Follow-up typically involves periodic urine flow tests and imaging to catch any early re-narrowing before symptoms return.