Hunner Lesions: Symptoms, Diagnosis, and Treatment

Hunner lesions are distinct inflammatory patches on the bladder wall found in a subset of people diagnosed with interstitial cystitis/bladder pain syndrome (IC/BPS), and they mark a condition that behaves differently from IC/BPS without lesions in almost every meaningful way: symptoms, tissue pathology, treatment response, and long-term outlook. Despite being recognized for over a century, Hunner lesions remain underdiagnosed partly because they can only be confirmed through cystoscopy, and many patients with bladder pain never receive one. Understanding what sets this subtype apart matters because the treatments that work best for it are specific to the lesions themselves.

What Hunner Lesions Actually Are

A Hunner lesion is an area of inflamed, reddened, and often cracked or denuded tissue on the inner lining of the bladder. The older term “Hunner’s ulcer” is misleading because these are not true ulcers in the way a stomach ulcer is. They are patches where the protective lining of the bladder (the urothelium) has broken down, surrounded by intense chronic inflammation that penetrates deep into the bladder wall. On cystoscopy, they appear as well-defined reddish areas that may have a characteristic central scar or crack, sometimes with small blood vessels radiating outward. When the bladder is stretched during hydrodistension, these patches often rupture and bleed.

The tissue under Hunner lesions tells a clear story of immune-driven damage. Biopsies show severe inflammation, with dense infiltration of immune cells, and significant loss of the urothelium compared to surrounding tissue. One histopathological study found that severe and moderate inflammation was far more common in bladder tissue with Hunner lesions than without them, and the remaining urothelium was significantly decreased in Hunner-type cases compared to both non-Hunner IC and healthy bladders.¹ Interestingly, that same study found that mast cell counts were actually higher in non-Hunner IC tissue, while Hunner lesion tissue was defined more by its raw inflammatory burden and urothelial destruction. A more recent analysis confirmed the higher frequency of combined acute and chronic inflammation in Hunner lesion biopsies compared to non-Hunner biopsies and also found more squamous metaplasia, a sign that the tissue is trying to protect itself by changing cell type.²

Who Gets Hunner Lesions

Among all patients diagnosed with IC/BPS, somewhere around 5 to 15 percent have Hunner lesions, depending on the study and whether cystoscopy was routinely performed. In one review of 359 patients who had cystoscopy under local anesthesia, about 12 percent had Hunner lesions.³ The true prevalence may be higher, since some patients never undergo the procedure needed to spot them.

Age is the most consistent demographic factor. Multiple studies converge on the finding that people with Hunner lesions are older than those without. One study found the median age was 58 in the Hunner group versus 41 in the non-Hunner group.⁴ The same pattern appeared in the cystoscopic review, which found that Hunner lesion prevalence was roughly twice as high in people over 50 compared to those under 50.³ Smaller bladder capacity also tracks with the Hunner subtype.⁵

How Symptoms Differ From Non-Hunner IC/BPS

The symptom profile of Hunner lesions overlaps with non-Hunner IC/BPS but is not identical. Both groups experience bladder pain, urinary urgency, and frequency. The differences show up when you look more closely.

People with Hunner lesions tend to report more nocturia (waking at night to urinate) and higher urinary frequency during the day.³ In one comparison, their nocturia symptom scores were significantly higher than the non-Hunner group’s.⁴ However, counterintuitively, the same study found that Hunner lesion patients reported less intense urologic pain on average than the non-Hunner group. This does not mean they suffer less overall. Close to half of Hunner lesion patients had non-urologic pain outside the pelvis, and their overall symptom burden, including comorbidities, tended to be higher.⁶

One interesting divergence: Hunner lesion patients were less likely to have a history of irritable bowel syndrome or anxiety attacks compared to non-Hunner patients.⁴ This fits with a growing understanding that the two subtypes may have fundamentally different underlying mechanisms. The non-Hunner form may involve more central pain sensitization and overlap with other chronic pain conditions, while the Hunner form is driven more by localized bladder inflammation.

How Hunner Lesions Are Diagnosed

There is no blood test or imaging scan that reliably identifies Hunner lesions. Diagnosis requires cystoscopy, a procedure in which a thin camera is passed into the bladder. The gold standard involves hydrodistension under anesthesia, where the bladder is filled with fluid to stretch the wall, making lesions and their characteristic bleeding patterns easier to see. The distinction matters for classification: if characteristic Hunner lesions are visible during cystoscopy, the condition is specifically classified as interstitial cystitis; if only scattered pinpoint bleeding (glomerulations) appears without lesions, the diagnosis is bladder pain syndrome without the IC designation.⁷

Researchers have looked for urinary biomarkers that could distinguish Hunner from non-Hunner disease without requiring cystoscopy. The results so far are disappointing for this specific purpose. While certain inflammatory markers in urine, such as TNF-alpha, can distinguish IC/BPS patients from healthy people with good accuracy, no single urinary biomarker has been found with both good sensitivity and specificity for telling Hunner and non-Hunner patients apart.⁸ One cytokine, MCP-1, has been found at significantly higher levels in urine from Hunner lesion patients, but it is not reliable enough on its own for diagnosis.⁶ For now, if you have IC/BPS symptoms and have never had a cystoscopy, a significant possibility remains unexamined.

Diagnosis can also be delayed by confusion with other conditions. The symptoms of Hunner lesions overlap with overactive bladder, chronic pelvic pain, urinary tract infections, and even bladder cancer. In rare cases, the cystoscopic appearance of inflamed lesions has led to an initial suspicion of malignancy before biopsy confirmed an inflammatory process.

Endoscopic Treatments That Target the Lesions Directly

Because Hunner lesions are discrete, visible patches, they lend themselves to direct treatment during cystoscopy. The main endoscopic options are ablation (destroying the lesion with electrocautery or laser), transurethral resection (surgically cutting out the lesion), and intralesional steroid injections. These are typically combined with hydrodistension of the bladder.

Ablation and Fulguration

Electrocautery fulguration burns the surface of the lesion to destroy the inflamed tissue. In one study of 14 patients who underwent endoscopic ablation, 12 had more than 50 percent symptom improvement, with 8 reporting complete relief. The mean improvement across all patients was 76 percent.⁹ All patients whose biopsies confirmed inflammatory cystitis responded well. Among those who had recurrence, repeat ablation was effective again.

Transurethral resection, a more thorough removal of the lesion, combined with hydrodistension has shown significant and sustained improvement in pain, quality of life, urinary frequency, and functional bladder capacity, with benefits maintained for at least 12 months in one study.¹⁰ Repeated procedures did not appear to cause bladder contraction over time, which had been a concern.¹¹

Steroid Injections Into the Lesion

Injecting a corticosteroid (triamcinolone) directly into the lesion during cystoscopy is a less destructive alternative. The idea is to suppress the local inflammation that drives the lesion without physically removing tissue. The results are encouraging. In one study, about 93 percent of patients had improvement in pain after one or more rounds of injections, and the number of other pain treatments they needed dropped significantly. More than half managed with triamcinolone alone, with no other pain medications. Of the seven patients in that study who had been on opioids, four were able to stop completely.¹²

Another study looking at triamcinolone injections found that preprocedure pain scores dropped by more than half, from an average of about 8 out of 10 down to roughly 4, and nocturia bother scores also improved significantly. About 72 percent of those patients needed only a single round of injections, with the average time to repeat treatment being about a year for those who needed it.¹³ A separate study reported that about three-quarters of patients had significantly improved scores at four weeks, and in roughly a third, the effect persisted for at least a year.¹⁴

Systemic Treatments for Hunner Lesions

When endoscopic approaches are not enough on their own, systemic medications enter the picture. The drug with the most evidence in Hunner lesions specifically is cyclosporine A, an immunosuppressant typically associated with organ transplant medicine. It makes sense in this context because the pathology is fundamentally an immune-mediated attack on the bladder wall.

In one multi-center study, 85 percent of patients with Hunner lesions initially responded to cyclosporine A, though some eventually stopped due to side effects, leaving a durable success rate of about 68 percent. In stark contrast, only 30 percent of patients without Hunner lesions responded to the same drug.¹⁵ Another study found that 84 percent of Hunner lesion patients met the threshold for treatment response, with significant improvement in pain, nocturia, daytime frequency, and a reduced need for repeat hydrodistension procedures.¹⁶

The catch with cyclosporine is its side effect profile. It can raise blood pressure, elevate blood sugar, and reduce kidney function. In one study, the average kidney filtration rate declined significantly at three months of treatment, though it returned to baseline after the drug was stopped.¹⁷ This means cyclosporine requires regular monitoring and is generally reserved for patients who have not responded adequately to endoscopic procedures or who need something to bridge between them.

Intravesical instillation of DMSO (dimethyl sulfoxide), a liquid anti-inflammatory agent placed directly into the bladder through a catheter, is another option. Small studies suggest DMSO works better in patients with Hunner lesions than in those without, again pointing to the inflammatory nature of the condition. In one comparison, patients with Hunner lesions who received DMSO showed significantly better outcomes in voided volumes and symptom scores than non-Hunner patients given the same treatment.¹⁸

Why Recurrence Is the Central Challenge

The biggest frustration with Hunner lesion treatment is that lesions come back. This does not mean treatment fails permanently; it means that managing this condition often requires a long-term plan involving repeated procedures rather than a one-time fix.

A prospective study tracking patients after transurethral ablation found that about 57 percent had recurrence requiring a second procedure. Of those who recurred, about 30 percent recurred again, needing a third.¹⁹ Where the lesions come back is telling: about half recurred at the original site, a small percentage appeared at entirely new locations, and around 42 percent recurred at a mix of old and new sites. The median time to first recurrence was about 8 to 13 months depending on the recurrence pattern. Another study found recurrence rates of roughly 13 percent at 6 months, 40 percent at 12 months, and 55 percent at 18 months.²⁰

The silver lining is that repeat treatments generally keep working. Each round of ablation, fulguration, or steroid injection can bring another stretch of relief. There is no evidence that repeated hydrodistension with fulguration leads to a shrunken or contracted bladder over time, which had been a theoretical worry.¹¹ The practical takeaway is that finding a urologist experienced with these procedures and planning for periodic re-evaluation is part of living with this condition, not a sign that treatment has failed.

Quality of Life and the Burden of Disease

The effect of Hunner lesion IC on daily life is severe and arguably underrecognized. One study that compared quality-of-life scores found that IC/BPS patients had health utility scores about 0.21 points lower than the general population, a gap three times larger than the reduction seen in patients with arthritis and roughly twenty times larger than the reduction in patients with cancer.²¹ IC/BPS patients were about 36 times more likely to report extreme problems with pain and discomfort, and about 9 times more likely to report extreme problems with anxiety, depression, and daily activities compared to patients without arthritis or cancer. Those are staggering numbers for a condition many people have never heard of.

This severity explains why Hunner lesion patients frequently cycle through multiple treatments and why researchers are increasingly vocal about the need for targeted therapies. Emerging research areas include monoclonal antibodies aimed at specific inflammatory pathways, regenerative approaches like platelet-rich plasma and stem cell therapy, and advanced drug delivery systems that could maintain anti-inflammatory medication inside the bladder for longer periods.²² None of these have become standard care yet, but the pipeline reflects a growing recognition that existing tools are insufficient for many patients.

Dietary Triggers and Flare Management

Beyond procedures and medications, most people with Hunner lesions manage a parallel daily effort to avoid symptom flares. Dietary modification is the most commonly used self-management strategy across all forms of IC/BPS, adopted by about 70 percent of patients in one survey.⁶

When patients were asked what they believed triggered their flares, over 94 percent could identify at least one dietary trigger, averaging about seven or eight triggers per person. The most commonly reported were citrus fruits, tomatoes, spicy food, alcohol, and caffeinated beverages, each cited by more than half of participants. A second tier of triggers, reported by about a third, included pineapple, cranberries, onions, yogurt, vinegar, chocolate, and carbonated beverages. Less common but still reported were pears, asparagus, beans, nuts, and aged cheese.²³ The common thread is acidity and irritation potential, which makes biological sense for a bladder wall that has lost its protective lining. Elimination diets, where suspected triggers are removed one at a time and reintroduced, remain the most practical approach, since individual sensitivities vary widely.

The Case for Treating Hunner Lesions as a Separate Disease

There is a growing push among specialists to stop lumping Hunner lesion disease in with the broader IC/BPS category. An expert working group has argued that the two should be formally separated because they differ in diagnosis, treatment response, and outcomes.²⁴ Their reasoning: historically, interstitial cystitis meant Hunner lesions and verifiable inflammation in the bladder wall. Applying the same label to patients with chronic bladder pain but no visible pathology muddles treatment guidelines, clinical trials, and patient expectations.

This is not just an academic naming dispute. When clinical trials include both Hunner and non-Hunner patients in one group, treatments that work well for one subtype get diluted by failure in the other. Cyclosporine’s dramatically different response rates in the two groups is a perfect example. The same may be true for other therapies that have shown “modest” results in mixed IC/BPS populations but might look very different if studied in Hunner-only cohorts. For patients, the practical implication is straightforward: if you have IC/BPS and have never had a cystoscopy under hydrodistension, you may be missing a finding that would fundamentally change which treatments are offered to you and how well they would be expected to work.