Typical Causes of Cystitis

The most common cause of cystitis is a bacterial infection. If bacteria reach the bladder, they multiply and irritate the bladder, causing the symptoms of cystitis. Bacteria can build up if you do not empty your bladder properly. Cystitis can also result from damage or irritation around the urethra. The urethra is the tube that carries urine from the bladder out of the body.