A urinary tract infection (UTI) is an infection in any part of your urinary system — your kidneys, ureters, bladder, or urethra. Most infections involve the lower urinary tract — the bladder and the urethra.
Women are at greater risk of developing a UTI than men. An infection limited to your bladder can be painful and annoying. However, serious consequences can occur if a UTI spreads to your kidneys.
Doctors typically treat urinary tract infections with antibiotics. But you can take steps to reduce your chances of getting a UTI in the first place.
Urinary tract infections don’t always cause signs and symptoms, but when they do, they may include:
- A strong and persistent urge to urinate
- A burning sensation when urinating
- Passing frequent, small amounts of urine
- Urine that appears cloudy
- Urine that appears red, bright pink or cola-coloured — a sign of blood in the urine
- Strong-smelling urine
- Pelvic pain in women, especially in the centre of the pelvis and around the area of the pubic bone.
UTIs may be overlooked or mistaken for other conditions in older adults.
Types of urinary tract infection
Each type of UTI may result in more specific signs and symptoms depending on which part of your urinary tract is infected.
|Part of the urinary tract affected
|Symptoms and signs
|Kidneys (acute pyelonephritis)
|Back pain or side (flank) pain
Shaking and chills
Lower abdominal discomfort
Frequent, painful urination
Blood in urine
|Burning with urination
When to see a doctor
Contact your doctor if you have signs and symptoms of a UTI.
Urinary tract infections typically occur when bacteria enter the urinary tract through the urethra and begin to multiply in the bladder. Although the urinary system is designed to keep out such microscopic invaders, these defences sometimes fail. When that happens, bacteria may take hold and grow into a full-blown infection in the urinary tract.
The most common UTIs occur mainly in women and affect the bladder and urethra.
- Infection of the bladder (cystitis). This type of UTI is usually caused by Escherichia coli (E. coli), a type of bacteria commonly found in the gastrointestinal (GI) tract. However, sometimes other bacteria are responsible.
Sexual intercourse may lead to cystitis, but you don’t have to be sexually active to develop it. All women are at risk of cystitis because of their anatomy — specifically, the short distance from the urethra to the anus and the urethral opening to the bladder.
- Infection of the urethra (urethritis). This type of UTI can occur when GI bacteria spread from the anus to the urethra. Also, because the female urethra is close to the vagina, sexually transmitted infections, such as herpes, gonorrhoea, chlamydia, and mycoplasma can cause urethritis.
Urinary tract infections are common in women, and many women experience more than one infection during their lifetimes. Risk factors specific to women for UTIs include
- Female anatomy – A woman has a shorter urethra than a man, which shortens the distance that bacteria must travel to reach the bladder.
- Sexual activity – Sexually active women tend to have more UTIs than do women who aren’t sexually active. Having a new sexual partner also increases your risk.
- Certain types of birth – Women who use diaphragms for birth control may be at higher risk than women who use spermicidal agents.
- Menopause – After menopause, a decline in circulating estrogen causes changes in the urinary tract that make you more vulnerable to infection.
Other risk factors for UTIs include
- Urinary tract abnormalities – Babies born with urinary tract abnormalities that don’t allow urine to leave the body normally or cause urine to back up in the urethra have an increased risk of UTIs.
- Blockages in the urinary tract – Kidney stones or an enlarged prostate can trap urine in the bladder and increase the risk of UTIs.
- A suppressed immune system – Diabetes and other diseases that impair the immune system — the body’s defence against germs — can increase the risk of UTIs.
- Catheter use – People who can’t urinate independently and use a tube (catheter) to urinate have an increased risk of UTIs. This may include people who are hospitalised, people with neurological problems that make it difficult to control their ability to urinate and people who are paralysed.
- A recent urinary procedure – Urinary surgery or an exam of your urinary tract that involves medical instruments can both increase your risk of developing a urinary tract infection.
When treated promptly and properly, lower urinary tract infections rarely lead to complications. But left untreated, a urinary tract infection can have serious consequences.
Complications of a UTI may include
- Recurrent infections, especially in women who experience two or more UTIs in a six-month period or four or more within a year.
- Permanent kidney damage from an acute or chronic kidney infection (pyelonephritis) due to an untreated UTI.
- There is an increased risk in pregnant women of delivering low birth weight or premature infants.
- Urethral narrowing (stricture) in men from recurrent urethritis, previously seen with gonococcal urethritis.
- Sepsis is a potentially life-threatening complication of an infection, especially if the infection works its way up to your urinary tract to your kidneys.
You can take these steps to reduce your risk of urinary tract infections:
- Drink plenty of fluids, especially water. Drinking water helps dilute your urine and ensures that you’ll urinate more frequently, allowing bacteria to be flushed from your urinary tract before an infection can begin.
- Drink cranberry juice. Although studies are not conclusive that cranberry juice prevents UTIs, it is likely not harmful.
- Wipe from front to back. Doing so after urinating and after a bowel movement helps prevent bacteria in the anal region from spreading to the vagina and urethra.
- Empty your bladder soon after intercourse. Also, drink a full glass of water to help flush bacteria.
- Avoid potentially irritating feminine products. Using deodorant sprays or other feminine products, such as douches and powders, in the genital area can irritate the urethra.
- Change your birth control method. Diaphragms, or unlubricated or spermicide-treated condoms, can all contribute to bacterial growth.
Tests and procedures used to diagnose urinary tract infections include:
- Analysing a urine sample – Your doctor may ask for a urine sample for lab analysis to look for white blood cells, red blood cells or bacteria. To avoid potential contamination of the sample, you may be instructed to first wipe your genital area with an antiseptic pad and to collect the urine midstream.
- Growing urinary tract bacteria in a lab – Lab analysis of the urine is sometimes followed by a urine culture. This test tells your doctor what bacteria are causing your infection and which medications will be most effective.
- Creating images of your urinary tract – If you are having frequent infections that your doctor thinks may be caused by an abnormality in your urinary tract, you may have an ultrasound, a computerised tomography (CT) scan or magnetic resonance imaging (MRI). Your doctor may also use a contrast dye to highlight structures in your urinary tract.
- Using a scope to see inside your bladder – If you have recurrent UTIs, your doctor may perform a cystoscopy, using a long, thin tube with a lens (cystoscope) to see inside your urethra and bladder. The cystoscope is inserted into your urethra and passes through to your bladder.
Antibiotics are usually the first-line treatment for urinary tract infections. Which drugs are prescribed and for how long depends on your health condition and the type of bacteria found in your urine.
Drugs commonly recommended for simple UTIs include:
- Trimethoprim/sulfamethoxazole (Bactrim, Septra, others)
- Fosfomycin (Monurol)
- Nitrofurantoin (Macrodantin, Macrobid)
- Cephalexin (Keflex)
The group of antibiotic medicines known as fluoroquinolones—such as ciprofloxacin (Cipro), levofloxacin, and others—isn’t commonly recommended for simple UTIs, as the risks of these medicines generally outweigh the benefits for treating uncomplicated UTIs. In some cases, such as a complicated UTI or kidney infection, your doctor might prescribe a fluoroquinolone medicine if there are no other treatment options.
Often, UTI symptoms clear up within a few days of starting treatment. But you may need to continue antibiotics for a week or more. Take the entire course of antibiotics as prescribed.
Suppose you have an uncomplicated UTI that occurs when you’re otherwise healthy. In that case, your doctor may recommend a shorter course of treatment, such as taking an antibiotic for one to three days. But whether this short course of treatment is enough to treat your infection depends on your symptoms and medical history.
Your doctor may also prescribe a pain medication (analgesic) that numbs your bladder and urethra to relieve burning while urinating, but the pain is usually relieved soon after starting an antibiotic.
If you have frequent UTIs, your doctor may make certain treatment recommendations, such as –
- Low-dose antibiotics, initially for six months but sometimes longer.
- Self-diagnosis and treatment are possible if you stay in touch with your doctor.
- A single dose of antibiotic after sexual intercourse if your infections are related to sexual activity.
- Vaginal oestrogen therapy if you’re postmenopausal.
For a severe UTI, you may need treatment with intravenous antibiotics in a hospital.
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