Patient education: Therapeutic phlebotomy (The Basics)

What is therapeutic phlebotomy? — "Phlebotomy" means drawing blood from a person. Usually, phlebotomy is done to take blood for lab testing. But "therapeutic" phlebotomy is done to treat a medical problem.

Therapeutic phlebotomy involves removing several "units" of blood. The units are removed 1 at a time, spread out over a few weeks or months. This lets the body make new blood cells in between. It also helps prevent anemia (a low number of red blood cells).

Therapeutic phlebotomy is similar to donating blood. It removes about the same amount each time.

Why might I need therapeutic phlebotomy? — Therapeutic phlebotomy can be used to treat conditions that cause a person to have too much iron in their body or too many red blood cells ("RBCs"). Examples of these conditions include:

●Hereditary hemochromatosis ("HH") – HH causes the body to take up and store too much iron. Too much iron in the blood can damage organs like the liver or heart. Most of the iron in the body is found in RBCs. When you remove RBCs, you also remove iron. The body makes new RBCs, and over time, the amount of iron stored in the body can go back to normal.

●Porphyria cutanea tarda ("PCT") – In PCT, sunlight causes severe blisters on the skin. Some people with PCT have too much iron in their bodies, and some do not. Removing iron by removing RBCs seems to treat PCT whether you have too much iron or not. Doctors do not completely understand why this works, but it is a very effective treatment.

●Polycythemia vera ("PV") – PV is a condition that causes the bone marrow to make too many RBCs. People with PV can have symptoms like headaches and itching. They are also at higher risk of blood clots. Removing some RBCs helps treat symptoms and reduce the risk of blood clots.

After your blood is drawn, your bone marrow starts making new RBCs. Your body uses iron to make new RBCs. This lowers the overall level of iron in your body. Often, therapeutic phlebotomy is done more than once to keep your iron levels or RBCs at a normal level.

How do I prepare for therapeutic phlebotomy? — Therapeutic phlebotomy can be done at an infusion center, blood bank, hospital, or even in a person's home. The staff will tell you if you need to do anything special to prepare.

Before your procedure, the doctor will order lab tests to check your blood counts or the amount of iron in your body. The results help the doctor decide if you need therapeutic phlebotomy.

You can eat and drink normally before therapeutic phlebotomy. In some cases, you might need to drink extra fluids the day before.

Ask the doctor or nurse if you have questions or if there is anything you do not understand.

What happens during therapeutic phlebotomy? — When it is time for the procedure:

●You will get an "IV," which is a thin tube that goes into a vein.

●Your blood will flow by gravity into a small bag. This can take between 1 and 4 hours, depending on how quickly the blood is drawn.

●The staff will watch you closely while your blood is being drawn.

●After you are finished, the staff will remove the IV and cover the area with a clean bandage.

In some cases, people with HH might be able to donate the blood that was removed.

What happens after therapeutic phlebotomy? — You will be asked to rest for a short time. You might have a snack or something to drink while you rest.

As you recover, you might feel dizzy or weak for a short time. Your arm might also be a little sore or bruised for a few days.

For the next day or so, you might want to:

●Avoid heavy exercise. Your doctor or nurse will tell you if there are specific activities you need to avoid.

●Avoid drinking alcohol.

●Drink a few extra glasses of water, unless your doctor told you to limit how much you drink.

●Rest if you feel tired.

What are the risks of therapeutic phlebotomy? — Your doctor will talk to you about all of the possible risks, and answer your questions. Possible risks include:

●Low blood pressure

●Feeling faint or dizzy

●Bruising

●Infection

●Anemia

When should I call the doctor? — Before you go home, make sure that you know what problems to look out for and when you should call the doctor. Make sure that you understand your doctor's or nurse's instructions. Ask questions about anything you do not understand.

Call for advice if:

●You have redness or swelling around where the IV went in.

●You faint or feel dizzy.

●You feel much weaker or more tired than you usually do after a therapeutic phlebotomy.

More on this topic

Patient education: Hemochromatosis (The Basics)
Patient education: Porphyria cutanea tarda (The Basics)
Patient education: Polycythemia vera (PV) (The Basics)

Patient education: Hereditary hemochromatosis (Beyond the Basics)