Urinary infections

What is a urinary tract infection (UTI)?

A urinary tract infection (UTI) is an infection of any part of your urinary system, which includes your bladder, urethra, ureters and kidneys. It's usually caused by bacteria, and can cause pain or a burning feeling when you wee, and needing to wee more often than usual.

What are the symptoms of a UTI?

Symptoms of a UTI can include:

• pain or a burning feeling when you wee
• needing to wee more often, more urgently, or more at night than usual, sometimes passing only a small amount
• cloudy, strong-smelling or blood-stained wee
• pain or discomfort in your lower abdomen, back or sides
• feeling tired or unwell.

If the infection has spread to your kidneys, you may also have a high temperature, chills, nausea or vomiting, and more severe pain in your back or side.

Children with a UTI may have a high temperature, seem generally unwell, wet the bed, or be sick. In older or frail people, and in those with a urinary catheter, a UTI can also cause sudden confusion or agitation, worse incontinence than usual, or new shivering.

What are the causes of UTIs and who is at risk?

UTIs are usually caused by bacteria that normally live in your bowel getting into your urinary tract through your urethra. E. coli is by far the most common culprit, responsible for more than 90% of bladder infections, though other bacteria, such as Klebsiella and Enterococcus species, and occasionally fungi, can also be responsible.

You're at greater risk of a UTI if you don't have a penis, since your urethra is shorter and sits closer to your anus, making it easier for bacteria to travel to your bladder. Other things that increase your risk include:

• pregnancy, or having been through the menopause
• conditions that block your urinary tract, such as kidney stones, or make it hard to fully empty your bladder, such as an enlarged prostate
• using a urinary catheter
• having a weakened immune system, for example from poorly controlled diabetes or chemotherapy
• using spermicide, or not drinking enough fluids.

Doctors sometimes describe UTIs as ‘uncomplicated’, meaning they happen in an otherwise healthy person, or ‘complicated, where there's an underlying cause such as a catheter, an abnormality in the urinary tract, or a weakened immune system.

Are there different types of UTI?

Yes, UTIs are described by which part of your urinary tract is affected:

• Urethritis is an infection of the urethra, the tube that carries urine out of your body
• Cystitis is an infection of the bladder, and it's the most common type of UTI
• A kidney infection (pyelonephritis) happens when the infection spreads up to one or both kidneys. This is less common but more serious.

Not every UTI turns into a bladder infection, and not every bladder infection spreads to the kidneys, but it's important to treat the infection promptly to stop it moving further up your urinary tract.

How is a UTI diagnosed?

A GP may test a sample of your urine to check for infection, although this isn't always necessary if your symptoms are clear.

Two main urine tests are used:

• Urinalysis: This checks your urine for blood and white blood cells, a sign your body is fighting infection
• A urine culture: This grows and identifies the specific bacteria present, usually within a few days, and helps guide the right antibiotic.

If you keep getting UTIs, or an infection doesn't clear up with treatment, you may be offered further tests, such as an ultrasound, a CT scan, or a cystoscopy (a thin camera used to look inside your bladder and urethra), to check for an underlying cause.

How is a UTI treated?

Most UTIs are treated with a short course of antibiotics, and it's important to finish the whole course even if you start feeling better. If you don't, the infection can come back and may be harder to treat.

Alongside antibiotics, you can help ease your symptoms and speed up recovery by:

• drinking plenty of fluids, especially water, to help flush bacteria out of your system
• taking paracetamol or ibuprofen for pain
• using a heating pad or hot water bottle on your abdomen or back
• avoiding drinks that can irritate your bladder, such as fruit juice, coffee and alcohol.

If you keep getting UTIs, your doctor may prescribe a low-dose antibiotic to take for several months, an antibiotic to take after sex, or, if you're perimenopausal or postmenopausal, a vaginal cream, gel or tablet containing oestrogen.

Men may need a longer course of antibiotics than women, since bacteria can move into the prostate gland and become harder to treat.

If a UTI spreads to your kidneys and you become very unwell, you may need antibiotics given directly into a vein, sometimes requiring a stay in hospital.

When should I see a doctor?

See a pharmacist first if you think you have a UTI and are a woman or girl aged 16 to 64 who isn't pregnant or breastfeeding. They can offer the same treatment as a GP.

Contact your GP or NHS 111 urgently if:

• you're 65 or older, or a child aged 15 or younger
• you're a man, or were assigned male at birth
• you're pregnant, have diabetes, use a catheter, or have a weakened immune system
• you have a high or very low temperature, or are shivering
• your symptoms are getting worse, or haven't improved within 48 hours of starting treatment
• you keep getting UTIs (2 within 6 months, or 3 within 12 months)
• you have pain in your lower abdomen or back, or blood in your urine.

Go to A&E or call 999 if you or the person you're caring for becomes confused, drowsy, or has difficulty speaking, or if you develop a fever, back pain and vomiting together, as this can mean the infection has reached your kidneys.