What is kidney failure and dialysis?

Chronic kidney disease (CKD) occurs when the kidneys stop working. The condition is also known as renal failure.

Kidney failure can be gradual or sudden and there are a number of stages of severity.

Stages of Chronic Kidney Disease

Effect on patient
Stage 1
Very mildly reduced kidney function. Rarely any symptoms.
Stage 2
Mildly reduced kidney function.
Stage 3
Moderately reduced kidney function.
Stage 4
Severely reduced kidney function.
Stage 5 - End Stage Renal Disease (ESRD)

Kidney function not sufficient to maintain life.

Treatment through some form of dialysis or a transplant is required.


The role of kidneys

Kidney diagramThe kidneys are located around the lower back, on either side of the body.

We usually have two kidneys, which have a number of functions including:

  • Production of urine.
  • Filtering waste products from the blood.
  • Helping to regulate blood pressure.
  • Maintaining the balance of salts and chemicals in the blood.
  • Hormone production to prevent other diseases, such as anaemia.

What happens when kidneys start to fail?

Kidneys are involved in many bodily processes, which means declining kidney function can cause:

  • tiredness
  • loss of appetite
  • frequent urinating
  • itching
  • swelling (particularly in the legs)
The kidneys can operate below their normal level without any obvious symptoms. This means chronic kidney disease can get worse over a period of years without being noticed.

When detected early, it is normally through a urine or blood test.

GPs and specialists are constantly working on new ways to pick up CKD before it gets to its later stages.

If you have not been diagnosed with kidney disease but are concerned, take this test on NHS Choices to see if you may be at risk. If you are still concerned, contact your GP and ask about having a kidney function test.

What happens when kidneys fail completely?

A person will produce little or no urine once the kidneys fail completely.

The body then fills with extra water and waste products. This condition is called uremia. Hands or feet may swell and the person will feel tired and weak because the body needs clean blood to function properly.

Untreated uremia can lead to seizures or a coma and will ultimately result in death.

Dialysis can help when kidneys fail

Any fluid a person with kidney failure takes on through food and drink must be removed from the body artificially.

This can be done by a treatment called dialysis.

In many cases a machine is used to artificially perform some of the lost roles of the kidneys, such as the removal of waste products and excess fluid.

There are two main types of dialysis:

  • Peritoneal dialysis - This can be performed at home by the patient and involves using the body’s own internal linings (the peritoneal membrane) to filter waste products and remove fluid throughout the day.
  • Haemodialysis - Depending on a patient’s situation, this can be carried out in hospital or at home.

Kidney transplant is another form of kidney replacement therapy.

Supporting End Stage Renal Disease (ESRD)

The SELFMADE study is aimed at those people living with ESRD undergoing treatment with haemodialysis in a hospital setting, to help patients, carers and staff make informed choices in both treatment and lifestyle.