A kidney infection is a type of urinary tract infection.
It usually happens when bacteria get into your kidneys from an infected bladder (cystitis).
Kidney infections can be serious and need fast treatment with antibiotics.
Symptoms of kidney infection
Symptoms of a kidney infection often appear within a few hours.
You can:
- feel sick
- have a pain in your back or side
- have a fever and shivers
You may also have symptoms of a urinary tract infection (UTI), such as:
- needing to pee suddenly, or more often than usual
- pain or a burning sensation when peeing
- smelly or cloudy pee
- blood in your pee
Non-urgent advice: Contact a GP if you have:
- a fever or feel hot
- pain in your tummy, lower back or genitals that does not go away
- symptoms of a UTI that do not improve after a few days
- blood in your pee
Urgent advice: Contact your GP immediately if:
- you think your child may have a kidney infection
If you cannot get a GP appointment, go to your nearest emergency department (ED).
What happens at your GP appointment
Your GP will ask about your symptoms and recent medical history.
They will do a pee test to see if you have a UTI.
Your GP may refer you to a doctor who specialises in the urinary system (urologist).
Treatment for kidney infection
Most kidney infections need fast treatment with antibiotics. This is to stop the infection from damaging the kidneys or spreading to the bloodstream. You may also need painkillers.
If your symptoms are severe or get worse, you may need to get antibiotics through a drip. You need to stay in a hospital for this treatment.
After taking antibiotics, you should feel better after about 2 weeks.
Causes of kidney infection
A kidney infection can happen after bacteria get into the tube that carries pee out of your body (urethra).
E. coli bacteria normally live in your bowel and cause no harm. They can get into your urethra during sex or when you wipe your bottom after you pee or poo.
From the urethra, the bacteria can:
- get into the bladder - this causes cystitis
- travel from the bladder to the kidneys - this causes a kidney infection
Most people with cystitis do not get a kidney infection.
A kidney infection can sometimes develop without a bladder infection.
For example, if you have:
- a problem with your kidney, such as kidney stones
- diabetes
- a weakened immune system
People most at risk of kidney infections
Kidney infections can happen at any age.
They are most common in women and people with a female urinary system. The female urethra is shorter than the male urethra. This makes it more likely for bacteria to reach the bladder or kidneys.
Younger women are most at risk because they tend to be more sexually active. Having frequent sex increases the chances of getting a kidney infection.
Some people are more likely to develop a kidney infection if they have a kidney disorder, such as:
- a blockage to the flow of pee from the kidney
- urinary reflux - where pee flows up from the bladder to the kidneys
Preventing kidney infections
The best way to prevent a kidney infection is to keep your bladder and urethra free from bacteria.
If you keep getting UTIs, your GP may prescribe you a low dose of antibiotics. This may help to prevent the infection returning. It may also prevent any infection spreading to the kidneys.
Do
-
drink plenty of fluids - water is best
-
pee when you feel the need to, rather than holding it in
-
pee after sex
-
wipe from front to back after you pee or poo
-
wash your genitals every day, and before having sex if possible
-
treat any constipation - this can make it harder to empty your bladder and increases your chance of getting a UTI
-
avoid using a diaphragm or condoms coated in spermicide if you often get UTIs
Content supplied by the NHS and adapted for Ireland by the HSE
