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Kidney failure (renal failure)

The words 'renal failure' are a doctor's way of saying your kidneys are not working properly. It is sometimes referred to as kidney disease or kidney failure instead.

Usually people have two kidneys. They help filter your blood by keeping all the good stuff (the nutrients and oxygen) and getting rid of all the bad stuff (toxins and waste). The waste leaves your body in your urine.

They also help control your blood pressure, the level of minerals in your bones and the production of red blood cells which carry oxygen round your body.

Watch our animation to find out more about how the kidneys work.

What causes kidney failure and who can get it?

There are lots of different reasons why our kidneys might fail but the older you get, the greater the risk. In a lot of patients the cause of the renal failure is unknown.

Other causes include:

  • diabetes
  • inflammation of the kidneys, which is called glomerulonephritis
  • polycystic kidney disease
  • renovascular disease, which causes the blood vessels to the kidney to fur up and is a common cause of the condition in older people
  • abnormalities of the kidneys and/or the urinary tract which develops when a person is just a foetus in the womb – this is a common cause of renal disease in children
  • certain medicines

What are the signs and symptoms of kidney failure?

Many people with kidney failure have no symptoms and it is often only diagnosed after routine blood tests.

Usually as the condition gets worse you will develop more obvious signs of the condition.

These can include:

  • poor appetite
  • nausea and vomiting
  • tiredness
  • fluid retention which can cause swollen ankles or shortness of breath
  • itching
  • cramps or restless legs

People with chronic renal failure might also find they need to pee more often, especially at night.

How is renal failure normally diagnosed and treated?

If you are suffering from symptoms of renal failure your doctor will run a number of tests to help make the diagnosis.

A lot of the symptoms can be caused by other illnesses and conditions so you will need to have your urine (pee) checked, as well as blood tests and an ultrasound of the kidneys.

If kidney failure is found you will be referred for treatment to a specialist renal unit.

If it's possible to treat the cause of kidney failure, this will be done. For example, if diabetes is causing the problem you will be treated for the diabetes.

If the cause of your kidney failure is not known you will be offered other treatment for the problem. The best treatment for serious cases – called end stage kidney failure – is usually a kidney transplant.

A transplant is a fairly big operation where a healthy kidney is put into your body in place of the one which is failing.

Sometimes you will have to wait for a suitable kidney to become available for transplant. You will join a waiting list of patients all waiting for the same thing.

Around 50 per cent of transplants are done when a living donors – such as a friend or relative – gives you one of their healthy kidneys.

Until a transplant becomes available you will be treated using dialysis. This is a machine which helps carry out the role of the kidneys, filtering out the waste products from the blood.

How dangerous is kidney failure?

It is an extremely serious condition and left untreated will result in something called end stage kidney failure, which is where dialysis or transplant becomes necessary.

For some people dialysis and even having a transplant does not work.

Is there anything you can do to prevent kidney failure?

In most cases kidney failure is caused by things which are out of your control.

But you can help keep your kidneys healthy and prevent the disease getting worse if you already have it by:

  • not smoking
  • avoiding anti-inflammatory drugs
  • eating a healthy, balanced diet
  • taking regular exercise
  • having your blood pressure checked regularly

When to ask for medical help

If you feel unwell or have any symptoms of kidney failure you should contact your doctor immediately for tests.

Looking forward

Kidney transplants have revolutionised life for many people with kidney failure.

Patients will still need to take medicines and have regular blood tests for life to check that the kidney is working well. But most recipients feel a lot better and are able to lead fairly normal lives.

The results of kidney transplantation have improved considerably over the last 20 years and research is constantly being done to look at ways to make it even better.

More information

Last reviewed by Great Ormond Street Hospital: 27 January 2010