Chronic renal failure Dr Rob Hicks There are many possible reasons why our kidneys fail, and the risk increases with age.

In this article

What causes it? What are the symptoms?

How's it treated? Transplant and dialysis

Advice and support

The most common causes of chronic renal failure (CRF) are:

• Diabetes (30 per cent of patients with diabetes develop kidney failure)
• Inflammation (for example, glomerulonephritis)
• High blood pressure
• Long-term infection
• Blockage (possibly due to kidney stones)
• Polycystic kidney disease
• Certain medicines

The risk of developing CRF increases after the age of 60.

Because the kidneys can manage with only a small proportion of their functional ability, it may be some time before any effects of gradual failure are noticed. Even when they do occur, the symptoms may be quite vague.

People with CRF may feel tired and lethargic. They may notice they go to the toilet to pass water more often, especially at night.

Other symptoms include itchy skin, nausea, impotence for men and fluid retention that makes the ankles swell or leaves you short of breath.

A doctor will look for signs of kidney failure and run a number of tests to help make the diagnosis, including urine tests, blood tests and a scan of the kidneys.

Treatment at a specialist kidney unit can help to slow the progression of CRF. In some cases it can delay or even avoid the need for dialysis or a kidney transplant.

If it's possible to treat the cause of kidney failure, this will be done. If another condition is present (such as high blood pressure or diabetes), keeping this under control can help prevent the kidney failure becoming worse.

What the kidneys do

The kidneys remove waste materials that collect in the blood as byproducts of normal bodily functions. They also produce some hormones and vitamin D, and maintain the body's mineral and water balance. Although we have two kidneys, you can remain healthy with just one.

Some dietary changes are needed to help the kidneys and a dietician will provide advice about this. Intakes of protein, sodium, potassium and fluids, for example, will need to be modified to ease the burden on the kidneys and ensure the body doesn't become overloaded.

Fortunately, there are fewer restrictions to the diet than there once were.

CRF can cause anaemia and bone disease to develop. Fortunately, both of these can be successfully treated with medication.

A kidney transplant is the best treatment for patients with CRF but there are more people needing kidneys than donor kidneys available. Until a transplant becomes possible, the role of the kidneys in filtering out the waste products from the blood can be performed through a process called dialysis.

There are two types of dialysis:

Haemodialysis - blood passes from the blood vessels through a machine that removes waste products and returns the blood to the body. This is performed three times a week in hospital and each session takes three to five hours.

Peritoneal dialysis - in continuous ambulatory peritoneal dialysis (CAPD), fluid in the peritoneal cavity (in the abdomen where the bowel is) is exchanged for fresh fluid. This process uses gravity to drain out old fluid and replace it with new fluid from a bag. It takes around 30 minutes and is performed at home three to four times a day. Automated peritoneal dialysis uses a machine to remove and replace this fluid. It's performed overnight and is more convenient than CAPD.

The type of dialysis used depends on many factors, including:

• Physical - for example, the degree of kidney function
• Emotional - for example, patient preference
• Social - for example, having a suitable home environment

It's important people with CRF eliminate risk factors for cardiovascular disease (for example, smoking) and are immunised against pneumococcal and influenza infections.

General advice

It's common for people with CRF to suffer from depression as a consequence of their condition, so psychological support should always be available.

National Kidney Research Fund

Helpline: 0845 300 1499
Email: kidneyhealth@kidneyresearchuk.org
Website: www.nkrf.org.uk

Carers UK

Carer's line: 0808 808 7777
Website: www.carersuk.org

This article was last medically reviewed by Dr Rob Hicks in January 2008