Cystitis - acute bacterial

Alternative names
Uncomplicated urinary tract infection; Acute urinary tract infection (UTI); Acute bladder infection

Cystitis is a bacterial infection of the bladder or lower urinary tract.

Causes, incidence, and risk factors

Cystitis occurs when the normally sterile lower urinary tract (urethra and bladder) is infected by bacteria and becomes irritated and inflamed. It is very common, occurring in more than 6 million Americans a year.

The condition frequently affects sexually active women ages 20 to 50 but may also occur in those who are not sexually active or in young girls. Older adults are also at high risk for developing cystitis, with the incidence in the elderly being much higher than in younger people.

Cystitis is rare in males. Females are more prone to the development of cystitis because of their relatively shorter urethra - bacteria do not have to travel as far to enter the bladder - and because of the relatively short distance between the opening of the urethra and the anus.

More than 85% of cases of cystitis are caused by Escherichia coli, a bacterium found in the lower gastrointestinal tract. Sexual intercourse may increase the risk of cystitis because bacteria can be introduced into the bladder through the urethra during sexual activity. Once bacteria enter the bladder, they normally are removed through urination. When bacteria multiply faster than they are removed by urination, infection results.

Risks for cystitis include obstruction of the bladder or urethra with resultant stagnation of urine, insertion of instruments into the urinary tract (such as catheterization or cystoscopy), pregnancy, diabetes, HIV, and a history of analgesic nephropathy or reflux nephropathy.

The elderly of both sexes are at increased risk for developing cystitis due to incomplete emptying of the bladder associated with such conditions as benign prostatic hyperplasia (BPH), prostatitis and urethral strictures. Also, lack of adequate fluids, bowel incontinence, immobility or decreased mobility and placement in a nursing home, all put people at increased risk for cystitis.


  • Pressure in the lower pelvis  
  • Painful urination (dysuria)  
  • Frequent or urgent need to urinate  
  • Need to urinate at night (nocturia)  
  • Abnormal urine color (cloudy)  
  • Blood in the urine (hematuria)  
  • Foul or strong urine odor

Additional symptoms that may be associated with this disease:

  • Pain during sexual intercourse  
  • Penis pain (rare)  
  • Flank pain  
  • Fatigue  
  • Fever  
  • Chills  
  • Nausea and vomiting  
  • Mental changes or confusion *

* Often in an elderly person, mental changes or confusion are the only signs of a possible urinary tract infection.

Signs and tests

  • A urinalysis commonly reveals white blood cells (WBCs) or red blood cells (RBCs).  
  • A urine culture (clean catch) or catheterized urine specimen may be performed to determine the type of bacteria in the urine and the appropriate antibiotic for treatment.


Because of the risk of the infection spreading to the kidneys (complicated UTI) and due to the high complication rate in the elderly population and in diabetics, prompt treatment is almost always recommended.

Antibiotics are used to control the bacterial infection. It is imperative that you finish the entire course of prescribed antibiotics. Commonly used antibiotics include:

  • Nitrofurantoin  
  • Sulfa drugs (sulfonamides) such as trimethoprim-sulfamethoxazole (Bactrim)  
  • Amoxicillin  
  • Cephalosporins  
  • Ciprofloxacin or levofloxacin  
  • Doxycycline

Chronic or recurrent UTI should be treated thoroughly because of the chance of kidney infection (pyelonephritis). Antibiotics control the bacterial infection. They may be required for long periods of time. Prophylactic low-dose antibiotics are sometimes recommended after acute symptoms have subsided.

Another medication called pyridium may be used to reduce the burning and urgency associated with cystitis. In addition, common substances that increase acid in the urine, such as ascorbic acid or cranberry juice, may be recommended to decrease the concentration of bacteria in the urine.

Follow-up may include urine cultures to ensure that bacteria are no longer present in the bladder.

Expectations (prognosis)
Most cases of cystitis are uncomfortable but disappear without complication after treatment.


  • Chronic or recurrent urinary tract infection  
  • Complicated UTI (pyelonephritis)  
  • Acute renal failure

Calling your health care provider

Call your health care provider if you have symptoms of cystitis.

Call your health care provider if you have cystitis and symptoms worsen, or new symptoms develop (especially fever, back or flank pain, or vomiting).


Keeping the genital area clean and remembering to wipe from front to back may reduce the chance of introducing bacteria from the rectal area to the urethra.

Increasing the intake of fluids may allow frequent urination to flush the bacteria from the bladder. Urinating immediately after sexual intercourse may help eliminate any bacteria that may have been introduced during intercourse. Refraining from urinating for long period of time may allow bacteria time to multiply, so frequent urinating may reduce risk of cystitis in those who are prone to urinary tract infections.

Drinking cranberry juice prevents certain types of bacteria from attaching to the wall of the bladder and may lessen the chance of infection.

Johns Hopkins patient information

Last revised:

Diseases and Conditions Center

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.