Nephrology

Urinary Tract Infection (UTI) — Clinical Reference

Last reviewed 2026-06-19 · TruelyserMD Clinical Reference
For Patients & General Readers

A urinary tract infection (UTI) is an infection in any part of your urinary system, which includes your kidneys, ureters, bladder, and urethra. UTIs are very common, especially in women, and can cause discomfort and pain. If left untreated, they can lead to more serious kidney infections.

Clinical Overview

UTIs are bacterial infections of the urinary tract, most commonly caused by Escherichia coli. They can range from uncomplicated cystitis to complicated infections involving the upper urinary tract (pyelonephritis) or presenting in specific populations like pregnant women or immunocompromised individuals.

Clinical Presentation

Signs & Symptoms

Symptoms (Patient-Reported)

  • Burning sensation when urinating
  • Feeling the need to urinate often, even if little urine comes out
  • Sudden, strong urge to urinate
  • Cloudy or strong-smelling urine
  • Pain in the lower abdomen or back
  • Feeling tired and unwell

Signs (Clinician-Observed)

  • Costovertebral angle tenderness (in pyelonephritis)
  • Suprapubic tenderness
  • Fever (especially in pyelonephritis)
  • Tachycardia

Differential Diagnoses

ConditionDistinguishing Feature
UrethritisOften presents with dysuria but may have less frequency/urgency and can be sexually transmitted (e.g., gonorrhea, chlamydia).
Vaginitis/VulvitisExternal burning and irritation, often with vaginal discharge; dysuria may be due to urine contamination of inflamed external genitalia.
Interstitial Cystitis/Painful Bladder SyndromeChronic pelvic pain and urinary symptoms without evidence of infection; often a diagnosis of exclusion.
Kidney StonesCan cause flank pain, hematuria, and sometimes urinary symptoms, but often presents with colicky pain and may have no signs of infection.
Prostatitis (in men)Can mimic UTI symptoms with dysuria, frequency, urgency, and pelvic pain, but may also involve fever, chills, and pain with ejaculation.
AppendicitisRight lower quadrant abdominal pain, nausea, vomiting, fever; can sometimes cause referred pain or irritation to the bladder causing urinary symptoms.

Red Flags — Seek Immediate Care

Key Investigations

Management Overview

Management of UTIs involves appropriate antibiotic therapy tailored to the suspected or confirmed pathogen and local resistance patterns. Uncomplicated cystitis can often be treated with short courses of oral antibiotics, while pyelonephritis may require longer courses, intravenous antibiotics, or hospitalization.

Disclaimer: This article is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and treatment. TruelyserMD does not replace clinical judgement.