Urinary tract infection (UTI) - including symptoms treatment and prevention

Urinary tract infection (UTI) is an infection of the urinary system. The normal urinary system consists of:

  • two kidneys
  • two ureters (the tube connecting the kidney to the bladder)
  • one bladder
  • one urethra (the tube connecting the bladder to the outside of the body).

Infection may occur in the kidneys (pyelonephritis), bladder (cystitis) or urethra (urethritis) or a combination of these.

The most common cause of a urinary tract infection is a bacterium commonly found in the gut called Escherichia coli (E. coli). It is usually spread to the urethra from the anus (back passage).

How an urinary tract infection is spread

Urine is normally free from bacteria, however, the normal human body is covered with bacteria and the normal intestine (bowel) contains large numbers of harmless bacteria. The structure of the urinary system prevents urine flowing upwards from the bladder to the kidney, so most urinary tract infections are in the bladder and are not usually serious.

However, if not treated, the infection may travel from the bladder up the ureters to the kidneys and cause a more serious infection which needs prompt medical attention.

Groups at risk

Some groups are at increased risk of having urinary tract infections:

  • women are vulnerable because the urethra is only 4cm long and bacteria only have to travel this short distance from outside the body to the inside of the bladder
  • people with urinary catheters, such as the critically ill, who cannot empty their own bladder
  • people with diabetes have altered immune systems and are more vulnerable to infection
  • men with prostate problems, since an enlarged prostate gland can cause the bladder to only partially empty
  • babies, especially those born with congenital abnormalities of the urinary system.

Signs and symptoms of a urinary tract infection

Urinary tract infections are very common, particularly in women, babies and the elderly. Around one in two women and one in 20 men will get a UTI in their lifetime.

Common symptoms of a UTI include:

  • burning or scalding sensation or lower abdominal discomfort when passing urine
  • passing urine much more frequently than usual
  • feeling an urge to urinate, but being unable to, or only passing a few drops
  • feeling the bladder is still full after urination
  • foul smelling urine
  • urine that is cloudy, bloody or dark
  • fever.

A person with a kidney infection can also experience:

  • chills
  • fever
  • loin (lower abdominal) pain
  • back pain.

A UTI in a child needs to be investigated as it may indicate a more serious condition. 

Vesico-ureteric reflux

The most common urinary system condition is vesico-ureteric reflux. This means the valve between the bladder and ureter is not working properly and allows urine to flow back to the kidney, increasing the risk of a kidney infection.

Since this disorder tends to run in families, it is important to screen children as early as possible if a close relative is known to have the problem.

Vesico-ureteric reflux and the associated infections can scar or permanently damage the kidney. It can also lead to:

  • high blood pressure
  • toxaemia in pregnancy (raised blood pressure, swelling and protein in the urine of the mother).
  • kidney failure.

Diagnosis of a urinary tract infection

A doctor may diagnose a UTI based on the symptoms. A simple test in the doctor’s surgery (urine dipstick) can provide evidence to support the diagnosis of a UTI. Sometimes a urine sample is sent to the laboratory for microscopy and culture to identify the specific cause of the infection and to help determine the correct antibiotic for treatment

Infectious period

(time during which an infected person can infect others)

UTIs cannot be passed from person-to-person except for those infections of the urinary tract that are sexually transmitted.

Treatment for a urinary tract infection

UTIs are usually treated effectively with antibiotics. However, as with any course of antibiotics, it is important to complete the full course prescribed, even if the symptoms have ended.

Prevention of a urinary tract infection

  • Exclusion from childcare, preschool, school or work is not necessary.
  • Drink lots of fluids to flush the urinary system. Water is best.
  • Urinate as soon as you feel the need rather than holding on.
  • For women and girls, wipe your bottom from front to back to prevent bacteria from around the anus entering the urethra.
  • Urinate shortly after sex to flush away bacteria that might have entered your urethra during sex.
  • Wear cotton underwear and loose-fitting clothes so that air can keep the area dry. Avoid tight- fitting clothes and nylon underwear, which trap moisture and can help bacteria grow.
  • Using a diaphragm or spermicide for birth control can lead to UTIs (in women) by increasing bacteria growth. Unlubricated condoms or spermicidal condoms increase irritation, which may help bacteria grow. Consider switching to lubricated condoms without spermicide or using a non-spermicidal lubricant.

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