Interstitial cystitis (IC) is a condition characterized by chronic bladder pain and urinary dysfunction. Despite its name, which may suggest a neurological disorder, the term “interstitial” refers to the tissue structure located between the bladder mucosa and the submucosal layer.
According to data from the Health Insurance Review and Assessment Service in Korea, the condition most commonly occurs in women between their 40s and 60s, and approximately 90 percent of patients are female. In male patients, the symptoms often overlap with those of prostatitis, which can lead to frequent misdiagnosis.
One of the most characteristic symptoms is that pain worsens as the bladder fills and improves after urination. This repeated cycle of pain and relief throughout the day significantly reduces the patient’s quality of life. Research suggests that while the average single urination volume of a healthy adult exceeds 250 mL, patients with interstitial cystitis often have an average voided volume of around 75 mL.
Diagnosis is not based on a single test but rather follows a “diagnosis of exclusion” approach, in which other possible conditions are systematically ruled out. The process typically begins with a detailed medical interview to evaluate the location of pain, urination patterns, and voiding volume. Urinalysis and urine culture are then conducted to check for bacteriuria, pyuria, or hematuria.
If these tests show no abnormalities, the likelihood of infectious disease decreases. Additional tests, such as urine PCR analysis, may then be performed to rule out other conditions that require differentiation, including urethritis or prostatitis.
A key step in the diagnostic process is cystoscopy. In some patients with interstitial cystitis, cystoscopic findings may reveal glomerulations—small bleeding points caused by rupture of microvessels beneath the bladder mucosa—or Hunner’s ulcers, which appear as reddish lesions on the bladder lining. Hunner’s ulcers are recognized in international guidelines, including the 2023 EAU Guidelines, as a representative finding that can confirm interstitial cystitis. When necessary, a biopsy may also be performed to definitively exclude other similar diseases.
However, these characteristic lesions do not appear in all patients. For this reason, the experience of the physician plays a critical role in diagnostic accuracy. The clinician must interpret the patient’s pain pattern, voiding diary, cystoscopic findings, and results of exclusion tests together in a comprehensive manner.
Dr. Choi Ho-cheol of Goldman Urology Clinic Dongtan Branch explained that interstitial cystitis often shows symptoms that fluctuate like waves, making it difficult to diagnose based on a single examination. He emphasized that carefully observing the timing of pain, whether symptoms improve after urination, and changes in voiding volume are essential elements in making an accurate diagnosis.
He further noted that chronic bladder discomfort that does not improve even after long-term antibiotic treatment may not simply be a case of ordinary cystitis. If symptoms such as frequent urination, pelvic pain, or pain during urination persist for several months, patients should seek consultation with a urology specialist rather than assuming the condition is simple cystitis or overactive bladder.