What is a urinary tract infection?
The urinary tract is comprised of the bladder, kidneys, ureters, and urethra.
A urinary tract infection (UTI) is an infection of any part of the urinary system. Most infections involve the lower urinary tract. UTIs are given different names depending on where they occur:
Bladder infection – cystitis
Urethra infection – urethritis
Kidney infection – pyelonephritis
The ureters are very rarely the site of infection.
Women are more likely to develop UTIs than men, due to anatomical differences; the urethra is shorter in women than in men, and it is closer to the anus, making it more likely that bacteria are transferred to the bladder.
Over 50 percent of all women will experience at least one UTI during their lifetime, with 20-30 percent experiencing recurrent UTIs.
Pregnant women are not more likely to develop a UTI than other women, but if one does occur, it is more likely to travel up to the kidneys; this is because of anatomical changes during pregnancy that affect the urinary tract.
As a UTI in pregnancy can prove dangerous for both maternal and infant health, most pregnant women are tested for the presence of bacteria in their urine, even if there are no symptoms, and treated with antibiotics to prevent spread.
Most UTIs are not serious, but some can lead to serious problems, particularly with upper urinary tract infections. Recurrent or long-lasting kidney infections (chronic) can cause permanent damage, and some sudden kidney infections (acute) can be life-threatening, particularly if septicemia (bacteria entering the bloodstream) occurs.
They can also increase the risk of women delivering low birth weight or premature infants.
Causes of urinary tract infections
The vast majority of UTI cases are caused by the bacterium Escherichia coli (E. coli), usually found in the digestive system. Chlamydia and Mycoplasma bacteria can infect the urethra but not the bladder.
People of any age and sex can develop a UTI; however, some people are more at risk than others. The following factors can increase the likelihood of developing a UTI:
Sexual intercourse (especially if more frequent, intense, and with multiple or new partners)
Poor personal hygiene
Problems emptying the bladder completely
Having a urinary catheter
Blocked flow of urine
Some forms of contraception
Procedures involving the urinary tract
Suppressed immune system
Immobility for a long period
Use of spermicides and tampons
Heavy use of antibiotics (which can disrupt the natural flora of the bowel and urinary tract)
Symptoms of urinary tract infections
Abdominal pains are a common symptom of urinary tract infections.
The symptoms of a urinary tract infection can depend on age, gender, the presence of a catheter, and what part of the urinary tract has been infected.
Common symptoms of urinary tract infection include:
Strong and frequent urge to urinate
Cloudy, bloody, or strong smelling urine
Pain or burning sensation when urinating
Nausea and vomiting
Muscle aches and abdominal pains
People with catheters may only experience fever as a symptom, making diagnosis more difficult.
Treatment of urinary tract infections
Drinking plenty of water helps flush out urinary tract infections and lowers the risk of future infection.
As urinary tract infections are normally caused by bacteria, they are most commonly treated with antibiotics or antimicrobials. The type of medication and length of treatment will depend on the patient’s symptoms and history.
The full course of treatment should always be completed for UTIs to make sure that the infection is fully clear, and to reduce the risk of antibiotic resistance. UTI symptoms can disappear before the infection has completely gone.
Drinking lots of fluids and frequently urinating are always recommended for people who have UTIs as this helps to flush out the bacteria. A variety of pain relief medications may be prescribed to alleviate pain. Applying a heating pad to the back or abdomen can also help.
An uncomplicated UTI is one that occurs in an otherwise healthy person with a normal clear urinary tract. These can usually be cured with 2-3 days of treatment.
A complicated UTI is one that occurs in a person who is weakened by another condition, such as pregnancy or heart transplant. Complicated UTIs tend to require longer periods of antibiotics, usually between 7-14 days.
To cure a UTI that is caused by problems within the urinary system, the underlying issue needs to be found and corrected. If left untreated, these infections can lead to kidney damage.
If the patient is seriously ill, they may need to be admitted to a hospital to ensure that they take in sufficient fluids and receive the right medication. Patients may also need to go to the hospital if they:
Are pregnant and are otherwise ill
Have cancer, diabetes, multiple sclerosis, spinal cord injury, or other medical problems
Have kidney stones or other changes in the anatomy of their urinary tract
Have recently undergone urinary tract surgery
Recurrent infections in women
Women who have recurrent bladder infections may be advised to:
Take a single dose of an antibiotic after sexual contact
Take a single, daily dose of an antibiotic for at least 6 months
Take a short course – 2-3 days – of an antibiotic if symptoms reappear
Have vaginal estrogen therapy if postmenopausal
There are several measures that can be taken to reduce the risk of developing a UTI:
Drink lots of water and urinate frequently
Avoid fluids such as alcohol and caffeine that can irritate the bladder
Urinate shortly after sex
Wipe from front to back after urinating and bowel movement
Keep the genital area clean
Showers are preferred to baths and avoid using oils
Sanitary pads or menstrual cups are preferred to tampons
Avoid using a diaphragm or spermicide for birth control
Avoid using any perfumed products in the genital area
Wear cotton underwear and loose-fitting clothing to keep the area around the urethra dry
Individuals are advised to contact a doctor if they develop the symptoms of a UTI, especially if they have developed the symptoms of a potential kidney infection (acute pyelonephritis).
Cranberry, probiotics, and UTIs
Cranberry extracts do not help treat existing UTIs but may help prevent the development of UTIs. This is because cranberries contain compounds (proanthocyanidins) that prevent E. coli from sticking to the walls of the digestive and urinary tract.
In a large meta-analysis, researchers found that women with recurrent UTIs who took cranberry over 12 months had a 35 percent reduction in infections. One large clinical trial found that 500 milligrams of cranberry extract taken daily for 6 months reduced the rate of UTI to the same extent as trimethoprim 100 milligrams, without posing a risk of antimicrobial resistance or super-infection in women with recurrent UTIs.
Cranberry extract tablets appear to be twice as effective as cranberry juice for preventing UTIs, which may be due in part to the sugar content of cranberry juice. Cranberry extracts also contain anthocyanins and salicylic acid, which may exert an analgesic and anti-inflammatory effect that can help alleviate UTI symptoms.