Urinary tract infection (UTI)

A urinary tract infection (UTI) is an infection in any part of your urinary system — your kidneys, ureters, bladder and urethra. Most infections involve the lower urinary tract — the bladder and the urethra.

Women are at greater risk of developing a UTI than men are. Infection limited to your bladder can be painful and annoying. However, serious consequences can occur if a UTI spreads to your kidneys.

Antibiotics are the typical treatment for a UTI. But you can take steps to reduce your chance of getting a UTI in the first place.

Symptoms Causes Risk factors Complications Prevention

Urinary tract infections don't always cause signs and symptoms, but when they do they may include:

  • A strong, persistent urge to urinate
  • A burning sensation when urinating
  • Passing frequent, small amounts of urine
  • Urine that appears cloudy
  • Urine that appears red, bright pink or cola-colored — a sign of blood in the urine
  • Strong-smelling urine
  • Pelvic pain, in women
  • Rectal pain, in men

UTIs may be overlooked or mistaken for other conditions in older adults.

Types of urinary tract infection

Each type of UTI may result in more-specific signs and symptoms, depending on which part of your urinary tract is infected.

Part of urinary tract affectedSigns and symptoms
Kidneys (acute pyelonephritis)
  • Upper back and side (flank) pain
  • High fever
  • Shaking and chills
  • Nausea
  • Vomiting
Bladder (cystitis)
  • Pelvic pressure
  • Lower abdomen discomfort
  • Frequent, painful urination
  • Blood in urine
Urethra (urethritis)
  • Burning with urination

When to see a doctor

Contact your doctor if you have signs and symptoms of a UTI.

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