Hemodialysis (pronounced: hee-mo-dye-AL-uh-sis) is a kind of kidney
dialysis. It's the one that doctors use most often to take over the kidneys'
job of filtering the blood.
Why Do People Need Hemodialysis?
Our kidneys work like a garbage collection system. They clean extra fluid and waste
from our blood. These wastes then leave the body as urine (pee).
If the kidneys stop working properly, waste can build up in the blood. That can
get dangerous. So people with kidney
to filter out the waste.
How Does it Work?
Hemodialysis uses a machine to pull blood out of the body, filter it, and pump
the clean blood back into the body again. The actual filtering happens in a part of
the machine called a dialyzer, or artificial kidney.
The dialyzer has two parts. One part is for blood. The other is filled with a cleaning
solution called dialysate.
The two parts of the dialyzer are separated by a thin membrane. Blood cells and
other important parts of the blood are too big to pass through the membrane. But waste
products and extra fluids go through it easily.
The dialysate pulls waste and extra fluids out of the blood, through the membrane,
and carries them away. The filtered blood is then pumped back to the body.
Blood flows from the body into the machine and back again through tubes. These
tubes are attached to needles in the person's skin. The needles go into a large vein
or artery through a vascular access. Doctors need to create this
vascular access before dialysis can begin.
Creating a vascular access involves minor surgery. Most patients are awake during
the procedure, but get local
to stop feeling in the area. Surgeons usually create the vascular access
a few weeks before hemodialysis starts. That way, the vascular access has time to
There are three different kinds of vascular access, but they all do the same job:
Fistulas and grafts connect arteries to veins
to make a bigger blood vessel. Surgeons usually create these types of vascular access
in a person's arm.
Sometimes doctors use a catheter to gain access to the blood
vessels. Catheters used for dialysis may go in the neck, chest, or other part of the
body. They're usually temporary until the person can get a fistula or graft.
When Is it Done?
Hemodialysis usually takes about 4 hours and has to be done three times a week.
Most people go to a special clinic — called a dialysis center — to
get their treatments. Some people get treatments at a hospital. Occasionally, dialysis
centers train families to do the treatments at home, but this isn't common.
After being hooked up to dialysis machines, patients lie down or sit in a chair.
While the treatment is going on, they might use the time to read, watch TV, play videogames,
Are There Any Risks?
Some people feel the needles as they go into the vascular access. After that, dialysis
treatments are painless.
Hemodialysis does have some risks, including:
Infection. Germs can get into the body at the site of a vascular
access and cause an infection.
Low blood pressure. Some people's blood pressure drops during
treatment. When this happens, the person might have trouble breathing, have a headache,
and feel sick (or throw up).
Itching. Hemodialysis can cause a person's skin to feel itchy,
especially during or right after a treatment.
Sleep problems. Some people getting dialysis can have trouble
sleeping (insomnia) or develop sleep apnea (when someone stops breathing for a short
time during sleep).
What Can I Do to Feel Better?
If you're doing dialysis, it helps to stay healthy. Taking good care of yourself
helps you avoid problems and get the most out of your treatments. Here are a few tips:
Eat the right foods. You'll need to get the right amount — not
too much or too little — of fluids, salt, vitamins, and minerals each day. Too much
potassium or phosphorus, for example, can affect your heartbeat or weaken your bones.
Your doctor or a dietitian at your dialysis clinic can give you advice on the right
meal plan for you.
Take medicine if your doctor prescribes it. You'll probably need
medicines to control your blood pressure, help produce red blood cells, and control
nutrient levels in your blood. Follow your doctor's instructions, and talk to your
doctor before taking any nonprescription medicines, vitamins, or other supplements.
Plan ahead. If you'll be traveling, make sure you'll be able
to continue your treatments. If you need to go to a dialysis clinic in a different
town, call ahead and make sure they can fit you into their schedule.
Kidney dialysis is a treatment
for kidney disease — it steps in to do the job of the kidneys and keep the body in
balance. But it's not a cure. Dialysis alone won't heal a person's failing
Some kinds of kidney disease get better and the person doesn't need dialysis anymore.
Other people stop getting dialysis because they have a kidney
Some people need dialysis treatments for the rest of their lives. In these cases,
people might switch back and forth between hemodialysis and another type of dialysis
dialysis, which usually can be done at home.