Patient education: Platelet count (The Basics)

What is a platelet count? — A platelet count is usually part of a blood test called a "complete blood count," or "CBC." It tells you how many platelets you have. Platelets are a type of blood cell that helps your blood clot.

If you have too few platelets, your body might bruise, bleed easily, or not be able to stop bleeding once it starts.

Having a platelet count that is too low or too high can be caused by a number of different health problems.

Why might I get a platelet count? — Your doctor might order this test:

●As part of a routine checkup

●If you have bleeding symptoms

●If you are at risk for having too many or too few platelets because of a medical condition

●Before you start taking a medicine called an "anticoagulant" (sometimes called a "blood thinner")

●To monitor your platelet count, if you have already been diagnosed with a platelet problem

●To check how treatments such as radiation or chemotherapy are affecting your platelet count, if you have cancer

●To test for certain other disorders with increased blood clotting

How do I prepare for a platelet count? — For this test, you need to get a "blood draw." Your doctor or nurse will tell you where to go for this. You do not need to change your diet or fast before the test.

It might help to wear a short-sleeve shirt when you get your blood drawn. This makes it easier for the person drawing your blood to get to your arm.

What happens during a blood draw? — For the blood draw, a needle is used to take a small amount of blood from your arm (figure 1). Collecting the blood only takes a few minutes. The blood is then tested in a lab.

Tell the person who takes your blood:

●If you take an anticoagulant medicine or if you have a bleeding problem – They will make sure that your bleeding is under control before you leave.

●If you have a latex allergy – Some of the supplies used for blood draws might contain latex.

●If you have a preferred arm to use

Getting blood taken does not usually cause problems. You might have a little soreness or bruising where the needle went in.

What do my results mean? — Your doctor or nurse will tell you when to expect your results and will contact you with the results. Or if you use an online "patient portal," you might get an alert there when your results are ready.

If your platelet count shows any abnormal results, your doctor or nurse will talk to you about what to do next. They might need to do more tests to figure out what the cause is, or they might change 1 of your medicines.

If you do have a health problem, your doctor will work with you to come up with a plan for treatment.

More on this topic

Patient education: Complete blood count (CBC) (The Basics)