What is dialysis?
Dialysis is a treatment for kidney failure. Kidney failure, also called renal failure, is a life-threatening condition. Healthy kidneys produce urine by filtering waste from your blood and controlling water levels in the body. Diseases or injury can damage your kidneys so they no longer perform these critical functions.
Kidney failure leads to a buildup of waste and fluid in the body. Dialysis substitutes for damaged kidneys by filtering waste products from the blood and regulating the amount of fluid in the body.
Chronic kidney failure occurs over a long period of time and can lead to permanent kidney damage and end-stage kidney failure. Treatment for end-stage kidney failure is life-long dialysis or a kidney transplant.
Acute kidney failure occurs suddenly. Acute kidney failure may go away after treating the cause. In this case, dialysis is a temporary treatment used until the kidneys heal.
Types of dialysis
There are two general types of dialysis. Discuss all of your dialysis options with your doctor to understand which option is right for you. The types of dialysis include:
- Hemodialysis is a procedure in which your blood flows from your body to a machine called a hemodialyzer. The hemodialyzer removes wastes, extra fluid, and other harmful substances from your blood. It then returns the blood to your body. A specialized hemodialysis team often performs hemodialysis in a hospital or outpatient dialysis center. Some patients are trained to perform hemodialysis in the home.
- Peritoneal dialysis is a procedure that you perform at home. It involves filling the space in your abdomen with a dialyzing solution through a small tube called a catheter. The catheter is surgically implanted in your abdomen and comes out below your belly button. The dialyzing solution draws wastes and extra water out of your blood through the small blood vessels in your abdomen. The solution, wastes, and extra body water then drain out of your abdomen through the catheter into a bag. There are two types of peritoneal dialysis. Continuous ambulatory peritoneal dialysis (CAPD) is a treatment you perform several times throughout the day without a machine. Ambulatory means that CAPD is adapted for staying mobile. You can take part in various activities with the solution in your abdomen. Continuous cycling peritoneal dialysis (CCPD) is a treatment in which a machine performs multiple cycles of dialysis during the night while you sleep.
Why is dialysis performed?
Your doctor may recommend dialysis to treat kidney failure. Kidney diseases, injury and other conditions can lead to kidney damage, poor kidney function, and possibly kidney failure. Doctors generally recommend dialysis when 85% to 90% of kidney function is lost.
Conditions that can lead to kidney failure include:
- Autoimmune diseases that attack the kidneys, such as lupus (systemic lupus erythematosus, or SLE). Autoimmune diseases occur when the body’s immune system attacks its own healthy cells and tissues.
- Diabetes, which can damage the kidneys over time if blood sugar is not properly controlled
- High blood pressure, which can damage the kidneys over time when not properly controlled
- Infections, such as repeated bladder, kidney or blood infections
- Kidney cancer, which can damage the kidneys
- Medications, such as intravenous (IV) drug abuse, overdose of certain drugs, or long term-use of certain medications, such as nonsteroidal anti-inflammatory drugs
- Nephritis and glomerulonephritis and other diseases that cause kidney inflammation and damage
- Polycystic kidney disease, an inherited disease that causes formation of large cysts in the kidneys
- Reduced blood flow to the kidneys due to shock or renal artery stenosis, which is a narrowing of the renal arteries
- Trauma or injury that affects the kidneys or the arteries that supply blood to the kidneys
- Urinary tract obstruction due to a kidney stone, tumor, congenital deformity, or enlarged prostate gland
Who performs dialysis?
A specialized dialysis team performs dialysis. A nephrologist leads the dialysis team. A nephrologist is a doctor who specializes in kidney diseases. Critical care medicine doctors (intensivists) also prescribe dialysis. These doctors specialize in caring for acute, life-threatening illnesses or injuries.