Urinary Tract Infection (UTI): Causes, Symptoms & Treatment

A urinary tract infection (UTI) is a bacterial infection of any part of the urinary system, including the urethra, bladder, ureters, or kidneys. Cystitis (bladder infection) is the most common type. UTIs are among the most common infections, affecting millions annually, particularly women. Most are acute and treatable with antibiotics, but complications can arise if left untreated.

Common causes:

• Ascending bacterial infection from urethra
• Escherichia coli (most common, 80-85%)
• Staphylococcus saprophyticus
• Other gram-negative bacteria

Risk factors include:

• Female gender (short urethra)
• Sexual activity
• Pregnancy
• Urinary retention
• Catheterization
• Diabetes
• Immunosuppression
• Urinary tract anomalies

Symptoms of cystitis include:

• Dysuria (painful urination)
• Frequency (polyuria)
• Urgency
• Suprapubic pain or pressure
• Cloudy or blood-tinged urine
• Foul-smelling urine

Pyelonephritis (kidney infection) presents with:

• Fever and chills
• Flank pain
• Nausea and vomiting
• Systemic symptoms

Diagnosis involves:

• Urinalysis (pyuria, bacteriuria)
• Urine culture (gold standard)
• Dipstick testing (nitrites, leukocyte esterase)

Treatment depends on infection type:

• Acute cystitis: 3-day course of trimethoprim-sulfamethoxazole or fluoroquinolones
• Pyelonephritis: fluoroquinolones or aminoglycosides
• Supportive care: hydration, analgesics

Antibiotic selection is guided by culture results and local resistance patterns.

Prevention strategies include:

• Adequate hydration (water intake)
• Frequent urination
• Post-coital voiding
• Cranberry products (modest evidence)
• Avoid irritants (douches, scented products)
• Proper genital hygiene
• Antimicrobial prophylaxis for recurrent UTIs

Seek care for dysuria, frequency, urgency, fever, or flank pain. Pregnant women with any UTI symptoms require treatment. Recurrent UTIs (more than 2 annually) warrant urological evaluation.