Causes

The urinary tract consists of the kidneys, bladder, ureters, and urethra. The urethra is the opening to the urinary tract where urine comes out. A UTI can be classified by the area of the urinary tract that it affects:
- When only the urethra is affected it is known as urethritis
- When the bladder is affected it is known as cystitis (the most common form of UTI)
- When the kidneys are affected it is known as pyelonephritis, which can cause kidney damage if left untreated.
Females are particularly at risk of getting a UTI because bacteria can more easily move into their urinary tracts due to the urethra and anus being close together. Other factors that can increase the risk of UTIs include:
- Diabetes
- Pregnancy
- Structural defects of the urinary tract
- Being sexually active
- Any factor that obstructs urine flow eg: kidney stones, an enlarged prostate
- Having a catheter inserted into the bladder
- Poor personal hygiene
- Being post-menopausal
- Using a diaphragm or spermicidal agents for birth control
- Having a weakened immune system.
Symptoms
The most common symptom of a UTI is a painful, burning sensation when passing urine. Other symptoms include:
- Pain in the abdomen or pelvic area
- A frequent or constant urge to urinate
- Cloudy or smelly urine.
When the kidneys are affected other symptoms experienced can include:
- Back pain
- Fever and chills
- Nausea and vomiting
- Blood-stained urine.
Some people with a UTI may have no symptoms at all, while some people who have these symptoms may not have a UTI. Symptoms in children may be less clear:
- Being generally unsettled
- Fever
- Abdominal pain
- Vomiting or diarrhoea.
- Fever
- Abdominal or back pain
- Vomiting that is persistent
- Shivering.
Diagnosis and treatment
If a UTI is suspected it is important to consult a doctor as soon as practicable so that an accurate diagnosis can be made and appropriate treatment given. Prompt treatment is important to prevent infection of the kidneys and other potential complications (such as sepsis) from developing. Until a doctor can be consulted, initial treatment measures include:
- Drinking lots of water
- Avoiding fluids that may irritate the bladder (eg. fizzy drinks, alcohol, coffee, and tea)
- Treating pain or fever with medications such as paracetamol.
UTIs are usually treated successfully with antibiotics. The course of antibiotics is taken orally, usually from three to ten days depending on circumstances.
Symptoms are usually relieved within 24 to 48 hours of the first dose of antibiotics being given, but it is important to finish the full course of antibiotics as prescribed to ensure that the infection does not come back, and to prevent the infection from becoming resistant to the antibiotic (i.e. the antibiotic will not work as well if the infection returns).
With more complicated and recurrent infections there may be an underlying cause such as urinary (vesicoureteral) reflux in children. If an underlying cause is suspected it needs to be identified and appropriately treated where possible. Diagnostic tests that may be used include ultrasound or computerised tomography (CT) scans and specialised x-rays of the urinary tract.
If there is a history of recurrent UTIs due to a known underlying cause, a cystoscopy may be performed to see inside the urethra and bladder, and low-dose antibiotics may be given daily for a period of weeks or months to prevent UTIs developing. If kidney infection develops, hospitalisation may be required so that antibiotics can be administered through a drip.
Prevention
The following general steps can help prevent a UTI developing:
- Drink plenty of water each day to avoid dehydration
- Pass urine when needed. Do not delay
- Urinate soon after sexual intercourse
- After toileting always wipe the bottom from front to back
- Shower rather than use a bath
- Do not use perfumed soaps or body wash
- Do not use sprays, powders, or douches of the genital area
- Stop smoking
- See a doctor as soon as possible if symptoms of a UTI are experienced.
References
Mayo Clinic (2019). Urinary tract infection (UTI) (Web Page). Rochester, MN: Mayo Foundation for Education and Research. https://www.mayoclinic.org/diseases-conditions/urinary-tract-infection/symptoms-causes/syc-20353447 [Accessed: 21/08/19]
Ministry of Health (2017). Urinary Tract Infection (Web Page). Wellington: Ministry of Health. http://www.health.govt.nz/your-health/conditions-and-treatments/diseases-and-illnesses/urinary-problems/urinary-tract-infection [Accessed: 21/08/19] O’Toole, M.T. (Ed.) (2017). Urinary tract infection (UTI). Mosby’s Dictionary of Medicine, Nursing & Health Professions (10th ed.). St Louis, MI: Elsevier.
Weinberg, G. A. (2018). Urinary tract infection (UTI) in children (Web Page). MSD Manual Consumer Version. Kenilworth, NJ: Merck and Co., Inc. https://www.msdmanuals.com/en-nz/home/children-s-health-issues/bacterial-infections-in-infants-and-children/urinary-tract-infection-uti-in-children [Accessed 26/08/19]
Updated – September 2019