What is Urinary Tract Infection (UTI)?

A UTI is an infection of the urinary system — most often the bladder — causing burning urination, frequency, and urgency; kidney infections can be serious and require prompt care.

Infectious Diseases

Urinary Tract Infection (UTI)

2025-09-15

Intro

UTIs are common, especially in women. Most are bladder infections (cystitis) with local symptoms; kidney infections (pyelonephritis) cause systemic illness and require prompt treatment.

Key Points

Classic symptoms: burning, urgency, frequency; fever/flank pain suggests kidney involvement.
Antibiotics are first-line for most symptomatic infections; choice depends on local resistance and patient factors.
Red flags needing urgent care: fever, flank pain, vomiting, pregnancy, sepsis signs.
Prevention: hydration, behavioral measures, topical estrogen after menopause (if appropriate).

Background

Enteric bacteria (commonly E. coli) ascend the urethra to the bladder; risk increases with sexual activity, pregnancy, obstruction, catheters, and post-menopause changes.

Causes or Mechanisms

Bacterial colonization and biofilm formation can promote recurrence. Structural or functional urinary tract problems increase risk.

Diagnosis / Treatment / Options

Diagnosis: symptoms + urine dipstick; urine culture for atypical, recurrent, pregnant, male, or complicated cases.
Treatment: short oral antibiotic courses for uncomplicated cystitis; longer courses/IV therapy for pyelonephritis; supportive care (fluids, analgesia). Consider addressing contributing factors (obstruction, catheter care).

Risks / Benefits / Prognosis

Most uncomplicated UTIs resolve quickly with treatment. Untreated or complicated infections can progress to kidney infection or sepsis.

FAQ

Q: Can cranberry help?
A: Evidence is mixed; some people find cranberry products reduce recurrences, but they are not a treatment for active infection.