Kidney infection (pyelonephritis)

5-minute read

Key facts

A kidney infection (also known as pyelonephritis) can make you very unwell, but will usually get better after treatment.
You may get recurrent kidney infections if you have a structural problem with your urinary tract.
Kidney infections are usually treated with antibiotics, which may be started in hospital.
If you have a kidney infection, you can lower the risk of damage to your kidneys by getting prompt treatment.

What is a kidney infection?

A kidney infection is one type of urinary tract infection (UTI). It may begin in a different part of the urinary tract, such as the urethra (tube that carries urine from the body) or bladder, and travel to one or both kidneys.

What causes a kidney infection?

Kidney infections are usually caused by bacteria. The bacteria can spread to the kidneys from a bacterial infection in the bladder.

You may be at a higher risk of getting a kidney infection if:

you are female
you have diabetes
you have a blockage in your urinary tract
you have a structural problem with your urinary tract
you have a urinary catheter
you have an enlarged prostate

What are the symptoms of a kidney infection?

If you have a kidney infection, you might have:

kidney pain, which you feel in your back or your side
nausea and vomiting
fevers and chills
smelly, cloudy or bloody urine
a burning pain when you pass urine
a need to pass urine more often than usual

If you think you might have a kidney infection, use healthdirect’s Symptom Checker as a guide to what to do next.

CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.

When should I see my doctor?

You should see your doctor if you have symptoms of a kidney infection, as you will usually need treatment with antibiotics.

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.

How is a kidney infection diagnosed?

Your doctor will ask about your symptoms and examine you. If they suspect you have a kidney infection, they may refer you for some tests. A urine test can help clarify whether there is an infection in your urinary tract.

You may need an ultrasound to make sure there is no blockage in your urinary tract. You might also have blood tests to check for infection in your blood.

How is a kidney infection treated?

If you have a kidney infection, you might need to start your treatment in hospital. At first, antibiotics are given through a drip (IV – intravenous drip). When your symptoms have improved enough, you can take your antibiotics orally (by mouth), which can be done at home.

If you are in pain, paracetamol may provide some relief. You can also ask your doctor what else might help.

If a blockage in your urinary tract has caused the kidney infection, you might need surgery urgently to correct the blockage.

How can I prevent a kidney infection?

You can reduce your risk of getting a kidney infection by drinking plenty of water and by seeing your doctor if you think you have a urinary tract infection.

If you tend to get urinary tract infections after having sex, then make sure you pass urine as soon as possible after sex.

Read more about how to prevent a urinary tract infection.