Kidney infection (pyelonephritis)

2-minute read

A kidney infection (also known as pyelonephritis) can make you very unwell, but will usually get better after treatment. If you think you might have a kidney infection, you should see a doctor as soon as you can. You can lower the risk of damage to your kidneys by getting prompt treatment.

Types of kidney infection

Kidney infections can be acute or chronic. If you have one, but it goes away after treatment, that condition is acute.

Chronic infection comes and goes, or may never go away properly. This type of infection can damage the kidneys. It usually occurs if there is a problem that causes urine to flow backwards from the bladder and up into the kidneys.

What causes a kidney infection?

Kidney infections are usually caused by bacteria. The bacteria can spread to the kidneys from a bladder infection. Some people with diabetes, or with a blockage in their urinary tract, are more likely to get a kidney infection.

Kidney infection symptoms

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.

Kidney infection diagnosis

Your doctor will talk to you and examine you. If they suspect you have a kidney infection, they may ask you to have some tests. A urine test can help determine 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 the bloodstream.

Kidney infection treatment

If you have a kidney infection, you might need to start your treatment in hospital. At first, antibiotics are given through a drip. When you have improved sufficiently, you can take your antibiotics orally (by mouth). You can do this 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, however, you might need surgery urgently.

Kidney infection prevention

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.