What is interstitial cystitis?

What is Interstitial Cystitis?

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic bladder condition defined as an unpleasant sensation (pain, pressure, or discomfort) perceived to be related to the urinary bladder, associated with lower urinary tract symptoms lasting more than six weeks, in the absence of infection or other identifiable causes. 1, 2

Core Clinical Features

Pain as the Defining Characteristic

• Pain is the hallmark symptom and must be present for diagnosis, though patients often describe it as "pressure" or "discomfort" rather than using the word "pain" 1, 3
• The pain typically localizes to the suprapubic region but frequently extends throughout the pelvis—including the urethra, vulva, vagina, rectum, lower abdomen, and back 1
• Pain characteristically worsens with bladder filling and improves with urination, which distinguishes it from other bladder conditions 3, 2, 4
• Pain often intensifies with specific foods or drinks 1, 2

Associated Urinary Symptoms

• Urinary frequency occurs in 92% of patients, though this is not specific to IC/BPS 1, 3, 2
• Urinary urgency is present in 84% of patients but differs qualitatively from overactive bladder 1, 3, 2
• IC/BPS patients experience a more constant urge to void and void to relieve pain, whereas overactive bladder patients have sudden compelling urges and void to avoid incontinence 1, 2, 4
• Nocturia is common 5, 6

Pathophysiology and Disease Understanding

• IC/BPS is a chronic inflammatory condition of the bladder wall that remains poorly understood 7
• The urothelium functions as an active sensor, releasing signaling molecules when stretched, with increased prostaglandin release during distension that sensitizes sensory nerves and amplifies pain 3
• Current theories include chronic infection, autoimmunity, neurogenic inflammation, or bladder urothelial defects 5
• The condition may represent a systemic disorder rather than purely a bladder problem, as evidenced by frequent coexistence with fibromyalgia, irritable bowel syndrome, chronic fatigue syndrome, Sjögren's syndrome, chronic headaches, and vulvodynia 1, 4

Clinical Course and Demographics

• IC/BPS is most commonly diagnosed in the fourth decade or later, though diagnosis is often delayed 1
• More than 90% of affected individuals are women, affecting over 700,000 people in the US 7
• Symptom flares are common, during which symptoms suddenly intensify for hours, days, or weeks 1, 4
• Initially, patients may report a single symptom such as dysuria, frequency, or pain 1
• 18-36% of women report a recent culture-proven UTI at presentation, though subsequent cultures are negative 1

Important Comorbidities and Associations

• High rates of mental health disorders including depression and anxiety are present, potentially sharing a common biological mechanism rather than being purely reactive 1, 4
• High incidence of prior pelvic surgery, especially hysterectomy, and levator ani pain in women 1, 4
• In women with chronic pelvic pain, IC/BPS frequently coexists with endometriosis, termed the "Evil Twins" syndrome 1, 3

IC/BPS in Men

• In men, IC/BPS shares clinical characteristics with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) 1, 2
• Men with pain, pressure, or discomfort perceived to be related to the bladder associated with urinary frequency, nocturia, or urgent desire to void should be strongly considered for IC/BPS diagnosis 1, 2
• Some men meet criteria for both conditions and may benefit from combined treatment approaches 1, 2

Critical Diagnostic Considerations

• The six-week symptom duration threshold allows for earlier treatment initiation compared to definitions requiring longer durations 1, 3
• IC/BPS is a diagnosis of exclusion requiring sterile urine cultures 1, 5
• Research or clinical trial definitions should never be used in clinical practice, as they lead to misdiagnosis and treatment delays 1, 2
• Cystoscopy is not required for all patients but should be performed when Hunner lesions are suspected 3, 2

Common Pitfalls

• Never treat with antibiotics when no infection is documented, as this leads to antibiotic resistance and disruption of protective flora 2, 4
• Many patients are initially misdiagnosed with recurrent UTIs despite negative cultures 1
• The condition is frequently overlooked and misdiagnosed due to the wide spectrum of presentations 1, 7
• Patients may deny "pain" but describe "pressure," requiring broad symptom descriptors during evaluation 1, 3