Kidney infection (pyelonephritis)

A kidney infection is one type of urinary tract infection (UTI). It usually begins in the urethra (the tube that carries urine from the body) and travels up the urinary tract to one or both kidneys.

Symptoms of a kidney infection can include:

• a sense of urgency when you need to pass urine (wee)
• a burning pain when you pass urine
• a need to pass urine more often than usual
• pain in your lower back or sides of your abdomen
• nausea and vomiting
• fever and chills

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, such as a kidney stone
• you have a structural problem with your urinary tract
• you have a urinary catheter
• you have an enlarged prostate

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

If you are very unwell, you may need to be treated in the emergency department or admitted to hospital for intravenous (IV) antibiotics.

Your doctor will ask about your symptoms and examine you. If they suspect a kidney infection, they may refer you for tests:

• A urine test can help clarify whether there is an infection in your urinary tract.
• An ultrasound or CT scan can check for a blockage in your urinary tract.
• Blood tests can check for infection in your blood.

If you have a kidney infection, you might need to start treatment in hospital with intravenous (IV) antibiotics directly into a vein. When your symptoms have improved enough, you may be able to take your antibiotics orally (by mouth) at home.

Kidney infections can lead to various complications including:

• septic shock
• kidney failure
• multiorgan failure

To prevent these complications, it is important to treat kidney infections promptly.

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, it's possible that passing urine as soon as possible after sex can reduce your chance of an infection, but the evidence is unclear.

Read more about how to prevent a urinary tract infection.

For more information about the symptoms, diagnosis, treatment and prevention of kidney infections, see Kidney Health Australia (Opens in new tab) and the Queensland Health (Opens in new tab) website.

Call healthdirect on 1800 022 222 at any time to speak to a registered nurse (known as NURSE-ON-CALL in Victoria) for more information and advice.

Do you prefer to read in languages other than English?

Health Translations (Opens in new tab) has an information sheet about urinary tract infections in a variety of community languages.

Looking for information for Aboriginal and/or Torres Strait Islander people?

See Australian Indigenous HealthInfoNet (Opens in new tab) for information about kidney health among Aboriginal and/or Torres Strait Islander people.