What is a urinary tract infection (UTI)?

Normal urine contains no bacteria (germs). Sometimes, however, bacteria from outside the body gets into the urinary tract and cause infection and inflammation. This is a urinary tract infection (UTI), which can involve the urethra (a condition called urethritis), kidneys (a condition called pyelonephritis), or bladder (a condition called cystitis). Cystitis is the most common type of urinary tract infection.

What causes a urinary tract infection (UTI)?

Normal urine is sterile and contains fluids, salts, and waste products. It is free of bacteria, viruses, and fungi. An infection occurs when microorganisms (usually bacteria from the digestive tract) cling to the opening of the urethra (the hollow tube that carries urine from the bladder to the outside of the body) and begin to multiply. Most infections arise from Escherichia coli (E. coli) bacteria that normally live in the digestive tract.

What are symptoms of a urinary tract infection (UTI)?

The following are the most common symptoms of a UTI. However, each child may experience symptoms differently. Symptoms in babies may include:

  • Fever
  • Abdominal fullness
  • Foul-smelling urine
  • Poor growth
  • Weight loss or failure to gain weight
  • Irritability
  • Vomiting
  • Poor feeding
  • Diarrhea
  • Lethargic (more tired)

Symptoms in older children may include:

  • Urgency to urinate (having "to go")
  • Wetting during day and/or night
  • Frequent urination
  • Painful or difficult urination
  • Discomfort above the pubic bone
  • Blood in the urine
  • Foul smelling urine
  • Nausea and/or vomiting
  • Fever
  • Chills
  • Pain in the back or side below the ribs
  • Fatigue
  • Small amount of urine while voiding despite feeling of urgency

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