Cases of confusion between interstitial cystitis and overactive bladder are increasing because the two conditions share similar urinary symptoms. Both can cause frequent urination and urgency, but experts emphasize that they differ clearly in their causes, main symptoms, and diagnostic approaches, making accurate differentiation essential.
Interstitial cystitis, also known as bladder pain syndrome, is characterized by chronic lower abdominal pain accompanied by urinary dysfunction. More than 90% of patients are women, making it significantly more common in females. In men, symptoms are often similar to prostatitis, which can delay diagnosis.
A key feature of interstitial cystitis is that pain worsens as the bladder fills with urine and is relieved after urination. Some patients experience severe urinary frequency, urinating more than 20 times per day, while the average voided volume per urination may decrease to around 75 mL, significantly lower than that of healthy individuals. Diagnosis requires excluding other conditions such as cystitis or prostatitis and confirming characteristic findings, including glomerulations or Hunner’s lesions, through cystoscopy.
Overactive bladder, on the other hand, occurs due to abnormalities in bladder nerve or muscle function. Its most notable symptom is a sudden and strong urge to urinate even when the bladder is not full. In some cases, patients may experience urge incontinence if they cannot suppress the urge. While frequent urination and nocturia are common, pain is typically absent, unlike in interstitial cystitis. Diagnosis is mainly based on symptom evaluation and bladder diaries, with endoscopic or imaging tests sometimes performed to rule out other diseases.
The most significant difference between the two conditions is the presence of pain. Interstitial cystitis is defined by pain as a core symptom, whereas overactive bladder primarily involves urgency without pain.
Experts stress that because the underlying causes differ, precise diagnostic evaluation is important. Misdiagnosis can lead to delayed treatment, worsening symptoms, and reduced quality of life.
Dr. Lee Jong-woo of Goldman Urology Clinic’s Dongtan branch explained that recording symptom patterns, pain intensity, and urination habits can be very helpful for diagnosis. He added that patients experiencing chronic pain or urinary dysfunction severe enough to interfere with daily life should seek evaluation from a urology specialist. He also emphasized that although interstitial cystitis and overactive bladder may appear similar, they are distinct conditions that can be effectively managed with appropriate, targeted treatment.