Simple urinary tract infections (UTIs) such as cystitis are extremely common.  Infants, girls and young women, and elderly men and women are most commonly affected.  There is often a sudden onset of dysuria and increased frequency. Suprapubic pain, haematuria and odorous or cloudy urine may also occur. Youngest and oldest patients, and the immunosuppressed, may not complain of all these symptoms.  Malaise, pyrexia, loin pain and nausea and vomiting, suggest upper tract infection and pyelonephritis.

Urine contains white blood cells and organisms (dipstick tests may show temporary blood and protein).  E.coli and other bowel organisms are the most common pathogens.

Predisposing factors

  • Age, sex
  • Abnormal urinary tract – especially incomplete bladder emptying (e.g. in prostatic hypertrophy)
  • Vesicoureteric reflux
  • Diabetes mellitus


All patients should have urine examined for blood cells and culture, and a dipstick examination for blood, protein and glucose.  Severe upper tract infections require blood cultures, blood count, renal function tests.

Antibiotics should be based on likely pathogens and local resistance patterns.  Treatment for 3 days gives higher success rate for cystitis than shorter courses.  Oral antibiotics should be combined with advice to take plenty of fluid.  Injected antibiotics may be required for pyelonephritis, and treatment is longer.  Asymptomatic bacteriuria should not usually be treated, except in pregnancy or if there are other risk factors for complicated infection.

Further investigations are indicated in infants, children, men with a single UTI, and women with pyelonephritis or frequent recurrences.  Ultrasound is usually adequate and can assess completeness of bladder emptying. CT urography or IVU gives better delineation of collecting system if required.  Isotope renogram may show scars of reflux nephropathy and can identify continuing reflux.

Further info