Urinary Tract Infection
Uncomplicated cystitis is a bladder infection confined to the lower urinary tract without systemic or upper-tract signs, per the IDSA 2025 classification.
Symptoms
Burning with urination, urinary urgency and frequency, and sometimes pelvic discomfort or cloudy, strong-smelling urine -- without fever or back pain, which would suggest the infection has spread.
Causes and risk
E. coli causes most cases. Female anatomy, sexual activity, and prior UTIs all raise risk.
How it is evaluated
Urinalysis, with urine culture when needed, confirms the diagnosis; imaging is reserved for recurrent or atypical cases.
Treatment
First-line therapy per the IDSA/ESCMID guideline is nitrofurantoin for 5 days, TMP-SMX for 3 days (only where local resistance is under 20% and the drug hasn't been used recently), or single-dose fosfomycin. Pivmecillinam is a newer first-line option following its 2024 FDA approval.
When to seek care
Fever, back or flank pain, nausea and vomiting, or feeling generally unwell suggest the infection has reached the kidneys (pyelonephritis) or become systemic, and need prompt evaluation rather than routine antibiotics alone.