CYSTITIS

acute or chronic inflammation of the urinary bladder. The bladder, the storage sac for urine, is lined with a mucous membrane and is highly resistant to infection. Occasionally, however, infections arise from such neighbouring organs as the kidneys and (in females) the vagina and urethra and (in males) the urethra and the prostate. Other conditions such as obstructions, tumour growths, physical injuries, and bladder stones can disrupt the bladder and leave it more vulnerable to infections. Infective agents that cause inflammation are bacteria, viruses, fungi, and parasites. The most common symptoms of cystitis are a burning pain during and immediately after urination, unusually urgent or frequent urinations, and lower back pain. Women are more susceptible to cystitis than men, chiefly because bacteria find easier access through the shorter female urethra than through the longer male urethra. The most common causative organism of cystitis in women is Escherichia coli, a bacterium that normally inhabits the intestines and is spread from the rectum to the urethra. Acute cystitis is usually caused by bacteria. The mucous membrane becomes swollen and red and bleeds. Small ulcers can develop, the surface layer can shred, and small, clear cysts (sacs with liquid, gas, or semisolid contents) frequently form. Abscesses may form. Chronic cystitis can result from a recurrent or persistent infection or from inflammation elsewhere in the body. Chronic infections, when there is no bladder obstruction, cause the walls of the bladder to become thickened and thus diminish the size of the cavity. If there is an obstruction as well as inflammation, the walls first become thickened and stretched and eventually tend to atrophy. A diagnosis of cystitis is made by microscopically examining the patient's urine and determining the presence in it of infective bacteria. In more severe cases, a physical examination is made of the bladder's interior using a special viewing instrument called a cytoscope. The treatment of cystitis may consist of surgical procedures or the administration of antimicrobial or other drugs.