A group of symptoms of unknown cause. It mainly affects women, and occasionally men, with pain and discomfort in the lower abdomen, a frequent urge to urinate and, in women, pain in the area of the vulva. Investigation rarely results in any abnormal findings. Post-menopausal women, who are the most common sufferers, may have inflammation of the vulva due to thinning of the tissues in that area. ‘Treatment involves advising the person to drink a lot of fluid and maintain a high standard of personal hygiene.