Contact Us
Simple, accurate health tests for the home and the workplace.

Kidney Infection


The kidneys

Your body has two kidneys one on each side of your abdomen, they are shaped like a bean. Each kidney is about the size of fist, the kidneys make urine, which then drains down the tubes (ureter’s) and into the bladder. The bladder then stores the urine until you pass it through the urethra when you go to the toilet. The kidneys jobs are to filter the blood of toxins and to produce urine to get rid of waste products from the body.

the kidneys

What is a kidney infection?

Kidney infection or pyelonephritis as it’s medically known is a type of urinary tract infection of one or both kidneys. Kidney infections can develop at any age and are usually more common in women, this is because women are more likely to get urine infections.

What causes kidney infections?

Kidney infections develop when bacteria from the bladder travels up the ureter and into one or both kidneys, this can happen when you have had the bladder infection cystitis. However, most people who have cystitis will not get a kidney infection. For more detailed information on cystitis click here.

A kidney infection that develops without a bladder infection is usually caused by a problem in the kidneys such as kidney stones or a blockage in one of the ureters. Occasionally bacteria can reach the kidneys from the bloodstream. For more information on kidney stones click here.

What symptoms are linked with kidney infections?

The following are symptoms that you may get with a kidney infection, symptoms can develop quite quickly. You may not have all these symptoms, some people with a kidney infection will just feel generally unwell.

  • A dull ache or pain in the lower back or abdomen where the kidneys are located.
  • Pain when passing urine.
  • Feeling of wanting to pass urine more often than usual and yet having very little urine to pass.
  • Urine may be dark or cloudy and contain blood.
  • A high temperature, fever and shivering
  • Foul smelling urine.
  • Nausea or vomiting.
  • Loss of appetite
  • Diarrhoea.

In older people a kidney infection can cause confusion. Children with kidney infections may wet the bed and be irritable. People who continue to get kidney infections may develop chronic pyelonephritis. However, this usually only happens if you have another underlying kidney problem such as large kidney stones. People with diabetes or  a weakened immune system are more likely to develop kidney infections.

How are kidney infections diagnosed?

Your doctor should be able to diagnose a kidney infection from your symptoms. However, they will be able to confirm the diagnosis with a urine test to find out what is causing your infection. Your doctor may also carry out a blood test to check for bacteria in the blood.

We sell a urine dip stick test for kidney infections on this website, for more information on this test or to buy click here.

A urine or blood test is usually all that is needed. However, your doctor may send a urine sample to a laboratory for analysis so they can see what bacteria is causing the infection and so the correct antibiotics prescribed. However, if your doctor believes an underlying problem, such as kidney stones may be the cause of an infection, then they may recommend that you have an x-ray, MRI scan or a CT scan. As kidney infections are less common in men and children further tests may be carried out.

How is a kidney infection treated?

Most kidney infections are treated with a course of antibiotics, some bacteria are resistant to some antibiotics so when the bacteria causing your infection is known a change of antibiotics may be required. Common antibiotics used to treat kidney infections are ciprofloxacin though trimethoprim might also be diagnosed. Painkillers can help ease the pain and reduce any temperature. We sell a range of painkillers on this website, to purchase click here.

When you have a kidney infection you must try to prevent dehydration, to do this drink at least 2 litres of water a day, unless you have another medical condition that means you are unable to drink that much. If well hydrated urine should be pale coloured.

In the majority of cases antibiotics will clear up the infection. However, in some cases you may need to be admitted to hospital, this may be because the infection is severe, your infection does not respond to antibiotics or you are at risk of dehydration from being sick or are going to the toilet a lot. In hospital antibiotics will be administered directly into one of your veins so that they work immediately.

Are there any complications from kidney infections?

Most people with kidney infections will make a full recovery. Occasionally kidney infections can cause an abscess in your kidney. If this occurs you may need surgery to remove the pus that has built up.

If your kidney infection is not treated then the bacteria can get into your bloodstream and this can lead to septicaemia (blood poisoning), which can be very serious.

Repeated kidney infections can lead to scarring and permanent damage to the kidneys. Your doctor will advise on the best way to manage this condition.

What can I do to prevent kidney infections?

As most kidney infections are caused by a bacteria infection like cystitis, the same things you would do to reduce cystitis will help prevent kidney infections. Never hold your urine, go as soon as you get the urge. Always wipe your bottom from front to back, to avoid spreading germs. Have a wee after sex and try to keep genitals clean. Drink plenty of fluids every day especially water.