Dialysis is a type of treatment that involves replicating many of the functions of the kidneys. It is often used to treat cases of kidney failure - also known as end stage renal disease - which is where the kidneys have been severely damaged and lost almost all of their functioning capacity.
The functions of the kidneys
The kidneys are two bean-shaped organs that are located at the back of the abdomen behind the liver and the intestines.
Every day, your kidneys filter your blood, removing waste products that are collected as part of your normal bodily functions, along with any excess fluid. The waste products and excess fluid become urine, which is stored in the bladder until you go to the toilet.
If the kidneys fail, an excess of waste products can build up in your blood, leading to a range of symptoms including:
- vomiting,
- itchy skin,
- fatigue, and
- swelling of the feet, hands, and ankles.
Without treatment, such as dialysis, kidney failure will inevitably prove fatal.
Types of dialysis
There are two types of dialysis:
- haemodialysis, and
- peritoneal dialysis.
Haemodialysis
Haemodialysis is the type of dialysis that most people are aware of. It involves inserting a needle into a blood vessel, which is attached by a tube to a dialysis machine. Blood is transferred from your body and into the machine, which filters out waste products and excess fluids. The filtered blood is then passed back into your body.
Peritoneal dialysis
Peritoneal is a less well known method of dialysis, although it is a method that is being used more commonly. Peritoneal dialysis involves using the peritoneum as a filter.
The peritoneum is a thin membrane (covering) that lines the inside of the abdomen, and surrounds and supports the abdominal organs, such as the stomach and the liver. Like the kidneys, the peritoneum contains thousands of tiny blood vessels, making it useful as a filtering device.
During peritoneal dialysis, a small flexible tube known as a catheter is attached to an incision in your abdomen, and a special fluid, known as dialysis fluid, is pumped into your peritoneal cavity. The peritoneal cavity is the space surrounding the peritoneum.
As blood moves through the peritoneum, waste products and excess fluid are moved out of the blood and into the dialysis fluid. The dialysis fluid is then drained out of the cavity.
Living with dialysis can be challenging because the treatment is associated with a range of side effects, such as fatigue and weight gain. However, there is plenty of help and support available, and many people are able to achieve a good quality of life while living with dialysis.