Cystitis

The most common cause of cystitis is a bacterial infection. If bacteria reach the bladder, they can multiply and irritate the bladder lining, causing the symptoms of cystitis.

A bacterial infection can be caused by not emptying the bladder fully. You may not be able to empty your bladder fully if:

• you are pregnant - as there is pressure on the pelvic area, or
• you have a blockage somewhere in your urinary system. This could be caused by a tumour or, in men, an enlarged prostate (a gland located between the penis and the bladder). 

Cystitis in females

In women, the opening of the urethra (the tube that passes from the bladder out of the body) is very close to the opening of the anus. There are often bacteria around the anus, which can be transferred to the urethra. From there, the bacteria can enter the bladder and cause irritation.

In women, cystitis is often caused by transferring bacteria in this way. This can happen when you are:

• inserting a tampon,
• having sex,
• wiping back to front when you go to the toilet (instead of front to back), or
• using a diaphragm (a soft dome made of latex or silicone) for contraception.

In menopausal women, the lining of the urethra and the bladder become thinned due to a lack of the hormone oestrogen. The thin lining is more likely to become infected and damaged. Women also produce less mucus around the vagina after the menopause. Without the mucus, bacteria are more likely to multiply.

Other causes

Cystitis can also be caused by damage, or irritation, in the area around the urethra in both men and women. This could be the result of:

• damage caused when changing a catheter (a tube inserted into the urethra to allow urine to flow into a drainage bag, which is often used after surgery),
• damage, or bruising, caused by vigorous, or frequent sex, sometimes called honeymoon cystitis,
• wearing tight clothing,
• chemical irritants - for example, in perfumed soap or talcum powder,
• other bladder, or kidney, problems, such as a kidney infection, or prostatitis, or
• diabetes (a long term condition caused by too much glucose in the blood).