Hunner Lesions and Hematuria/Pain Characteristics
Hunner lesions can cause hematuria (both gross and microscopic), but this is not a defining feature, and pain in interstitial cystitis/bladder pain syndrome (IC/BPS) is typically worse with bladder filling rather than when empty.
Hematuria in Hunner Lesions
While hematuria can occur with Hunner lesions, the evidence shows it is neither specific nor particularly common:
Hematuria is not a distinguishing feature: A study comparing 86 Hunner lesion patients to 137 non-Hunner lesion IC/BPS patients found microscopic hematuria in 31% of Hunner lesion cases versus 21% of non-Hunner cases—a difference that was not statistically significant 1.
Overall IC/BPS hematuria prevalence: Up to 41% of IC/BPS patients (regardless of Hunner lesion status) may experience at least one episode of hematuria, though this rarely indicates serious pathology 2.
Cystoscopic bleeding pattern: During cystoscopy with hydrodistention, Hunner lesions characteristically show a "waterfall bleeding pattern" when the reddened mucosal area splits at distension 3. This is a diagnostic finding during the procedure itself, not necessarily spontaneous bleeding into urine.
Clinical workup required: The 2022 AUA guidelines explicitly state that "a proper hematuria workup should be performed in patients with un-evaluated hematuria" to exclude bladder cancer, stones, and other confusable conditions 4.
Pain Pattern in IC/BPS
The pain pattern in IC/BPS, including Hunner lesion disease, follows a characteristic bladder-filling pattern:
Pain worsens with bladder filling: IC/BPS is fundamentally characterized by "bladder/pelvic pain and pressure/discomfort associated with urinary frequency and strong urge to urinate" 4. This indicates pain increases as the bladder fills.
Low-volume frequency pattern: The guidelines emphasize documenting "a low volume frequency voiding pattern that is characteristic of IC/BPS" 4. Patients void frequently precisely because bladder filling causes discomfort.
Pain relief with voiding: While not explicitly stated in the provided evidence, the clinical pattern of frequent voiding to avoid bladder distension implies that emptying provides some relief.
Clinical Pitfalls
Important caveat: Clinical parameters alone cannot reliably distinguish Hunner lesion from non-Hunner lesion disease. The study found no significant differences in symptom duration, history of gross hematuria, comorbid disease, or pain scores between the two groups 1. This is why cystoscopy is essential for accurate diagnosis when Hunner lesions are suspected 4.
The presence or absence of hematuria should not be used to rule in or rule out Hunner lesions—cystoscopy remains the only reliable diagnostic method 4, 1.