A 70-year-old female with frequent urination and burning on urination; what is the most likely diagnosis?

• A. Renal calculi.
• B. Urinary tract infection.
• C. Renal cancer.
• D. Pelvic inflammatory disease.

Answer: (B)

Frequent urination and burning with urination are classic irritative symptoms of a lower urinary tract infection, specifically cystitis. In older adults, this scenario is most commonly caused by bacteria ascending from the urethra to the bladder, triggering inflammation of the bladder mucosa and resulting in urgency, frequency, and dysuria. The usual culprit is E. coli, though other uropathogens can be involved. The other conditions don’t fit this symptom pattern: renal calculi often produce severe flank or groin pain with possible blood in the urine rather than just burning and frequent urges; renal cancer typically presents with painless hematuria, weight loss, or a palpable mass; pelvic inflammatory disease involves lower abdominal/pelvic pain with cervical motion tenderness and is more common in sexually active younger women. So the presentation most strongly points to a urinary tract infection.