Urinary Tract Infection (UTI)

Infection beginning in the urethra but that can extend into the urinary bladder, ureter, and kidneys.

Natural protections against UTI include:

• Acidic pH of urine.
• Urea in urine.
• Prostatic / distal urethral mucous secretions.
• Unidirectional urine flow.

Cystitis

Infection of the lower urinary tract (urethra, bladder, and ureters). Risk of infection increases with the time a urinary catheter remains in place.

Risk factors for cystitis include:

• Shorter urethra.
• Post-menopausal.
• Urine stasis.
• Bacterial contamination.

Signs and symptoms of cystitis include:

• Urinary urgency and frequency.
• Dysuria.
• Pyuria (seen as cloudy urine).
• Hematuria (seen as amber-colored urine).
• Lethargy and confusion (particularly in the elderly).

Cystitis can be asymptomatic.

Pyelonephritis

Occurs when cystitis ascends the ureters to infect the kidneys themselves. Treatment requires antibiotics. Risk of pyelonephritis increases with vesicoureteral reflux— when a defective valve allows urine to flow back into the ureter.

Signs and symptoms of pyelonephritis include:

• S/S of cystitis
• Flank tenderness and pain.
• Fever, malaise, chills.

WBC casts of the glomerulus and nephron may be seen during infection.

The lifecycle of pyelonephritis typically follows:
1. Oliguria due to damaged nephrons.
2. Polyuria due to immature replacement cells.
3. Normal urination.