Cases of confusion between interstitial cystitis and overactive bladder are increasing due to their similar voiding symptoms. While both conditions cause frequent urination and urgency, it is pointed out that accurate differentiation is essential due to clear differences in their etiology, main symptoms, and diagnostic methods.
Interstitial cystitis, also known as 'bladder pain syndrome,' is characterized by chronic lower abdominal pain accompanied by voiding dysfunction. It is particularly common in women, with over 90% of all patients being female. In men, symptoms often resemble those of prostatitis, leading to delayed diagnosis.
This condition typically presents with pain intensifying as the bladder fills with urine and alleviating after urination. Severe frequent urination, sometimes exceeding 20 times a day, can occur, and the average voided volume per urination is significantly reduced to approximately 75mL, much lower than the average for healthy individuals. For diagnosis, other conditions such as cystitis or prostatitis must first be ruled out, followed by cystoscopy to identify characteristic lesions like glomerulations or Hunner's ulcers.
In contrast, overactive bladder arises from abnormal nerve and muscle function in the bladder, with its most prominent feature being strong urgency even when the bladder is not significantly full. Inability to suppress this urgency can lead to urge incontinence. Frequent urination and nocturia are common, but unlike interstitial cystitis, there is usually little to no pain. Diagnosis is primarily made through symptom evaluation and voiding diaries, with endoscopy or imaging tests used to rule out other conditions if necessary.
The most significant difference between the two conditions is the 'presence or absence of pain.' In interstitial cystitis, pain is a core symptom, whereas in overactive bladder, urgency acts as the primary discomfort without pain.
Experts emphasize the importance of precise differential diagnosis because the etiologies of the two conditions are different. An incorrect diagnosis can lead not only to delayed treatment but also to worsening symptoms and a decline in quality of life.
Dr. Lee Jong-woo, director of Goldman Urology Dongtan Branch, stated, “Recording symptom patterns, pain intensity, and voiding habits is very helpful for diagnosis. Especially if daily life is difficult due to chronic pain or voiding dysfunction, an accurate diagnosis should be sought from a urology specialist.” He further emphasized, “Since interstitial cystitis and overactive bladder are clearly distinct conditions, symptoms can be effectively improved through systematic treatment.”