RELATED STORIES • Dialysis: Managing your medications • Hemodialysis and peritoneal dialysis: What's the difference? • Slide show: A step-by-step look at hemodialysis • Hemodialysis: Compare conventional and daily treatment schedules • Dialysis medications: What they do, what to watch for • Peritoneal dialysis: A flexible treatment option for kidney failure • Slide show: A step-by-step look at peritoneal dialysis • Potential complications of dialysis • Video: Hemodialysis

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Your kidneys contain millions of tiny blood vessels that filter waste from your blood and eliminate it in your urine. But diabetes and other diseases can damage this delicate filtering system. If your kidney function dips too low, your doctor may recommend dialysis.

There are two types of dialysis: hemodialysis and peritoneal dialysis. Either of these can bide time until a possible kidney transplant. If you're considering hemodialysis, here's what you need to know.

Hemodialysis is a procedure in which a machine filters harmful waste and excess salt and fluid from your blood. A needle is inserted into your arm through a special access point. Your blood is then directed through the needle to a machine called a dialyzer, which filters your blood a few ounces at a time. The filtered blood returns to your body through another needle.

If your kidneys are failing, you may need dialysis to help control your blood pressure and maintain the proper balance of fluid and various chemicals — such as potassium and sodium — in your body. Dialysis also helps your body maintain the proper acid-base balance.

Sometimes kidney failure is caused by a specific kidney disease. In other cases, it's a complication of another condition, such as:

• Diabetes
• High blood pressure (hypertension)
• Kidney inflammation (glomerulonephritis)
• Inflammation of blood vessels (vasculitis)
• Polycystic kidney disease

Before you start hemodialysis, a surgeon creates a vascular access point for blood to leave for cleansing and then re-enter your body during treatment. There are three types of access points:

• Temporary access. If you need emergency hemodialysis, the surgeon may insert a plastic tube (catheter) into a large vein in your neck or near your groin. The catheter is temporary. If it's left in place for too long, you face a risk of infection, clotting in the catheter and stenosis (narrowing) of surrounding blood vessels.
• Arteriovenous (AV) fistula. A surgically created AV fistula is a connection between an artery and a vein, usually in the forearm. Once the connection is made, faster flowing arterial blood flows into the vein — causing it to grow larger and stronger. This makes repeated needle placements for hemodialysis easier. An AV fistula may take six weeks or longer to heal, but it can last for many years. An AV fistula is less likely than other types of access points to form clots or become infected.
• Arteriovenous (AV) graft. If your blood vessels are too small to form an AV fistula, the surgeon may instead connect an artery and a vein with a synthetic tube. This tube functions like an artificial vein, usually in your forearm or upper arm. An AV graft often heals within two to three weeks. With proper care, an AV graft may last several years — but it's more likely to form clots and become infected than is an AV fistula.

Ideally, the access point is created weeks or even months before you need hemodialysis.

Vascular access is a vital part of hemodialysis. Take special care to prevent injury and infection:

• Keep the access area clean.
• Don't use the arm with the access point for blood pressure readings or to draw blood samples not associated with the dialysis treatment.
• Don't lift heavy objects or put pressure on the arm with the access point.
• Don't cover the access point with tight clothing or jewelry.
• Check the pulse in the access point every day.
• Ask the nurse or technician to check the access point before each treatment.
• Don't sleep with the access arm under your head or body.

If your access point stops working, the surgeon can create a new access point in your other forearm, your upper arm or your groin. Or you may consider peritoneal dialysis, another type of dialysis done through a catheter inserted in your abdomen.

Most people receive hemodialysis three times a week, about three to five hours at each session. This type of hemodialysis, known as conventional hemodialysis, is usually done in a dialysis center. During each session you can read, watch TV, or do crossword puzzles or other sedentary activities.

At some dialysis centers, you can choose shorter but more frequent treatments. This is known as daily dialysis. It's usually done six days a week for about two to two and a half hours. Although conventional hemodialysis is more common, people who choose daily hemodialysis often report greater improvements in blood pressure and quality of life.

With special training and someone to help you, it's possible to do hemodialysis at home. If you're comfortable doing the procedure yourself and keeping records for your health care team, the benefits are appealing. Your quality of life will likely improve, you'll save yourself travel time to and from the dialysis center, and you'll have more flexibility about when to do your treatments — perhaps even at night while you sleep.

Eating the right foods can improve your dialysis results and your overall health. While you're receiving hemodialysis, you'll need to carefully monitor your intake of fluids, protein, sodium, potassium and phosphorus. Your dietitian will help you develop an individualized meal plan based on:

• Your weight
• Your personal preferences
• How well your kidneys still function
• Other medical conditions you might have, such as diabetes or high blood pressure

While you're receiving hemodialysis, you'll likely need various medications:

• Blood thinners to prevent clots in the hemodialysis machine and tubing
• Blood pressure medication to control your blood pressure
• Erythropoietin to stimulate your bone marrow to produce new red blood cells
• Calcium, iron and other nutritional supplements to control the level of certain nutrients in your blood
• Phosphate binders to prevent the buildup of phosphorus in your blood
• Stool softeners and laxatives to manage constipation

Your doctor will do frequent blood tests to monitor your condition.

Your kidneys play a role in many of your body's systems. When your kidneys stop working, these other systems don't work as well as they did before. This can lead to various complications, including:

• Lack of red blood cells (anemia)
• Bone diseases
• High blood pressure
• Fluid overload
• Inflammation of the membrane surrounding the heart (pericarditis)
• High potassium levels, which can affect your heart rhythm
• Nerve damage
• Infection
• Heart disease

Dialysis of any type is a serious responsibility. Whether you choose to have hemodialysis at home or in a dialysis center — or you opt for peritoneal dialysis — your health is in your hands. Weigh the pros and cons of each treatment option with your health care team to help decide what's best for you.