Cystitis: Causes and symptoms

The causes of cystitis vary according to sex because of the differences in anatomical structure of the urinary tract.

Most bladder infections in women are so-called ascending infections, which means that they are caused by disease agents traveling upward through the urethra to the bladder. The relative shortness of the female urethra (1.2–2 in in length) makes it easy for bacteria to gain entry to the bladder and multiply. The most common bacteria associated with UTIs in women include Escherichia coli (about 80% of cases), Staphylococcus saprophyticus, Klebsiella, Enterobacter, and Proteus species. Risk factors for UTIs in women include:

• Sexual intercourse. The risk of infection increases if the woman has multiple partners.
• Use of a diaphragm for contraception
• An abnormally short urethra
• Diabetes or chronic dehydration
• The absence of a specific enzyme (fucosyltransferase) in vaginal secretions. The lack of this enzyme makes it easier for the vagina to harbor bacteria that cause UTIs.
• Inadequate personal hygiene. Bacteria from fecal matter or vaginal discharges can enter the female urethra because its opening is very close to the vagina and anus.
• History of previous UTIs. About 80% of women with cystitis develop recurrences within two years.

The early symptoms of cystitis in women are dysuria, or pain on urination; urgency, or a sudden strong desire to urinate; and increased frequency of urination. About 50% of female patients experience fever, pain in the lower back or flanks, nausea and vomiting, or shaking chills. These symptoms indicate pyelonephritis, or spread of the infection to the upper urinary tract.

Most UTIs in adult males are complications of kidney or prostate infections. They are usually associated with a tumor or kidney stones that block the flow of urine and are often persistent infections caused by drug-resistant organisms. UTIs in men are most likely to be caused by E. coli or another gram-negative bacterium. S. saprophyticus, which is the second most common cause of UTIs in women, rarely causes infections in men. Risk factors for UTIs in men include:

• Lack of circumcision. The foreskin can harbor bacteria that cause UTIs.
• Urinary catheterization. The longer the period of catheterization, the higher the risk of UTIs.

The symptoms of cystitis and pyelonephritis in men are the same as in women.

Hemorrhagic cystitis, which is marked by large quantities of blood in the urine, is caused by an acute bacterial infection of the bladder. In some cases, hemorrhagic cystitis is a side effect of radiation therapy or treatment with cyclophosphamide. Hemorrhagic cystitis in children is associated with adenovirus type 11.

— Rebecca J. Frey