The exact cause of interstitial cystitis isn't known, but it's likely that many factors are at play. For instance, people with interstitial cystitis may also have a defect in the protective lining (epithelium) of the bladder. A leak in the epithelium may allow toxic substances in urine to irritate your bladder wall.

Other suggested but unproven factors that may contribute to interstitial cystitis include an autoimmune reaction, heredity, infection or allergy.

Jan. 02, 2014