Hemodialysis requires several pieces of equipment and many supplies for each treatment. The hemodialysis machine, dialyzer, dialysis solution, and needles are four of the most important parts in hemodialysis treatments:

• Hemodialysis machine: The hemodialysis machine at a dialysis center is about the size of a microwave. Machines for home hemodialysis are small enough to sit on an end table. The hemodialysis machine has three main jobs:

1. Pump blood and regulate blood flow through the dialyzer
2. Monitor blood pressure
3. Control the rate of fluid removal from your body

Blood is removed from the body through one needle and propelled by a blood pump, which is, essentially like a rolling pin on the outside of the tube. The blood passes through the dialyzer and then is returned to the body through the other needle. Along the way, there are blood pressure monitors and detectors to ensure the procedure is safe. The blood, while it does pass outside of the body, remains inside the tubes or in the dialyzer and does not actually go into the hemodialysis machine.

• Dialyzer. The dialyzer is the “artificial kidney.” Blood enters at the top of the dialyzer, in this case, and is forced into multiple, very thin, hollow fibers made of a semi-permeable membrane. Each fiber is about the size of a human hair. As blood passes through the hollow fibers, dialysis solution passes in the opposite direction on the outside of the fibers. In the less than one second it takes for the blood to pass from the top of the dialyzer to the bottom, waste products diffuse out of the blood and into the dialysis solution.

• Dialysis Solution. Also known as dialysate, dialysis solution contains water and added substances that allow the safe removal of wastes and extra salt and fluid from your blood during dialysis. Your doctor will prescribe a specific dialysis solution for your treatments. If you have problems such as low blood pressure or muscle cramps during your treatments, your doctor can prescribe a solution with a different balance of chemicals. Your doctor might also adjust your solution if your blood tests show that your blood has too much or too little of certain minerals, such as potassium (A mineral and electrolyte found in the body and in many foods.)or calcium.

• Needles. You, a nurse, or a technician will insert two needles into a vein, usually in the arm, at the start of each hemodialysis treatment. One needle draws blood that goes to the dialyzer, and the other needle returns the filtered blood to your body. When you first start hemodialysis treatments, the needle insertions may be one of the most uncomfortable parts of the treatment. Most people get used to them after a few treatments. If you find the needle insertions painful, you can put a numbing cream or spray on your skin so you won’t feel the needles.

Many people who have their treatments at a dialysis center have their needles inserted by a nurse or technician; however, you may prefer to insert your own needles. You’ll need training on inserting needles properly to prevent infection and keep your vein healthy. With a little practice, you can become good at inserting needles. Whether you insert your own needles or have it done by a nurse or technician, you should learn how to care for the area where the needles are inserted to prevent infection.