Some people are more prone to developing recurrent urinary tract infections than others. First and foremost, being female is a risk factor – a short urethra makes women more vulnerable to this disease.
Are sexually active. Sexual intercourse can lead to bacteria "penetrating" the urethra.
Use certain methods of contraception. Women who use diaphragms and other membranes soaked in spermicidal gel are more likely to suffer from cystitis.
Pregnancy. Hormonal changes during pregnancy can increase the risk of cystitis.
Are in menopause. Altered hormone levels in menopausal women often provoke UTIs.
Obstruction of urine flow. This can be caused by a bladder stone or an enlarged prostate (in men).
Changes in the immune system. These occur in diseases such as diabetes, HIV infection, and chemotherapy for cancer. Suppression of the immune system increases the risk of bacterial and, in some cases, viral cystitis.
Long-term use of urinary catheters. In older people and people with certain diseases, long-term use of urinary catheters may be necessary. This often leads to increased vulnerability to bacterial infections, as well as direct damage to the tissues of the bladder.