Interstitial cystitis (IC), also called Painful Bladder Syndrome, is a chronic condition in which the walls of the bladder are irritated and inflamed. Although it is often diagnosed as a bladder infection, IC does not appear to be directly caused by an infection. It is a relatively uncommon condition that affects approximately one in 300 people. Ninety percent of those diagnosed with IC are women. Women of any age can suffer from it but it is most often diagnosed during a woman's reproductive years.

IC can be very painful and is often one of the underlying causes of chronic pelvic pain. It may also be more common in women with other chronic health conditions, including:

• irritable bowel syndrome
• rheumatoid arthritis
• fibromyalgia
• asthma and allergies
• systemic lupus erythematosus

Most women with the condition experience pain, which often increases as the bladder fills and may be relieved by urination. A woman with IC may also have a constant pain in the bladder, abdomen, lower back, vagina or thighs.

IC usually interferes with normal urination patterns so that a woman may need to urinate more urgently, more frequently or both. Both the pain and urinary symptoms are often worse in the days before a woman's menstrual period.