What is kidney failure?
Kidney failure happens when the kidneys fail to function properly.
Kidney failure is also known as established renal failure (ERF) or end-stage kidney disease.
What do the kidneys do?
The kidneys are two bean-shaped organs located on either side of the body, just beneath the ribcage. They carry out a number of important functions including:
- Filtering out waste products and excess water from the blood before converting them into urine
- Helping maintain blood pressure
- Maintaining the correct levels of chemicals in the body which will help the heart and muscles function properly
- Produce a type of vitamin D that keeps bones healthy
- Producing a substance called erythropoietin, which helps stimulate the production of red blood cells
How common is kidney failure?
Over three million people in the UK have chronic kidney disease (CKD) and an estimated 13,000 people die from the disease each year.
These numbers are expected to rise over the next 10 years.
Most people with CKD have a mild form, but some develop kidney failure and require treatment with dialysis or a transplant.
Kidney disease is more common among older people. It is estimated that about one in five men and one in four women between the ages of 65 and 74 has some degree of CKD.
Kidney disease is also more common among black people and those from south Asia. The reasons for this include higher rates of diabetes and high blood pressure in these populations.
CKD is graded in five stages from the mildest form of the condition to the most severe. These stages are determined by how efficient the kidneys are at cleaning the blood - known as the glomerular filtration rate (GFR).
Normal kidneys are capable of cleaning at least 90 millilitres a minute.
Established renal failure is said to have occurred when this falls to 15 millilitres a minute or less, or a patient already needs dialysis. This is classed as Stage 5 CKD. However, a patient will probably need dialysis or a kidney transplant by the time their kidney filtration rate falls below 30 millilitres a minute - classed as Stage 4 CKD.
About 1% of people with Stage 3 CKD - where there is a moderate drop in filtration rates - will go on to develop kidney failure.