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
Urinary tract infections are much more common in adults than in children, but about 1%-2% of children do get urinary tract infections.
These infections are much more common in girls and women than in boys and men younger than 50 years of age. The reason for this is not well understood, but anatomic differences between the genders (a shorter urethra in women) might be partially responsible.
About 40% of women and 12% of men have a urinary tract infection at some time in their life
Lower urinary tract infection
Bladder (cystitis): The lining of the urethra and bladder becomes inflamed and irritated.
Dysuria: pain or burning during urination
Frequency: more frequent urination (or waking up at night to urinate, sometimes referred to as nocturia); often with only a small amount of urine
Urinary urgency: the sensation of having to urinate urgently
Cloudy, bad-smelling, or bloody urine
Lower abdominal pain or pelvic pressure or pain
Mild fever (less than 101 F), chills, and “just not feeling well” (malaise)
Urethra (urethritis): Burning with urination
Upper urinary tract infection (pyelonephritis)
Symptoms develop rapidly and may or may not include the symptoms for a lower urinary tract infection.
Fairly high fever (higher than 101 F)
Flank pain: pain in the back or side, usually on only one side at about waist level
In newborns, infants, children, and elderly people, the classic symptoms of a urinary tract infection may not be present. Other symptoms may indicate a urinary tract infection.
Newborns: fever or hypothermia (low temperature), poor feeding, jaundice
Infants: vomiting, diarrhea, fever, poor feeding, not thriving
Children: irritability, eating poorly, unexplained fever that doesn’t go away, loss of bowel control, loose bowels, change in urination pattern
Elderly people: fever or hypothermia, poor appetite, lethargy, change in mental status
Pregnant women are at increased risk for an UTI. Typically, pregnant women do not have unusual or unique symptoms. If a woman is pregnant, her urine should be checked during prenatal visits because an unrecognized infection can cause pregnancy complications.
Although most people have symptoms with a urinary tract infection, some do not.