Platelet count

Thrombocyte count

A blood sample is needed.

Most of the time you do not need to take special steps before this test.

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. This soon goes away.

The number of platelets in your blood can be affected by many diseases. Platelets may be counted to monitor or diagnose diseases, or to look for the cause of too much bleeding or clotting.

The normal number of platelets in the blood is 150,000 to 400,000 platelets per microliter (mcL) or 150 to 400 x10^9/L.

Normal value ranges may vary slightly. Some lab use different measurements or may test different specimens. Talk to your doctor about your test results.

LOW PLATELET COUNT

A low platelet count is below 150,000. If you do not have enough platelets, you may bleed too much.

If your platelet count is below 50,000, your risk of bleeding is much higher. Even every day activities can cause bleeding. If your platelets are low, you need to know how to prevent bleeding and what to do if you are bleeding.

A lower-than-normal platelet count is called thrombocytopenia. Low platelet count can be divided into 3 main causes:

• Not enough platelets are being made in the bone marrow
• Platelets are being destroyed in the bloodstream
• Platelets are being destroyed in the spleen or liver

3 of the more common causes of this problem are:

• Cancer treatments, such chemotherapy or radiation
• Drugs and medicines
• Autoimmune disorders, in which the immune system mistakenly attacks and destroys healthy body tissue, such as platelets

HIGH PLATELET COUNT

A high platelet count is 400,000 or above

A higher-than-normal number of platelets is called thrombocytosis. It means your body is making too many platelets. Causes may include:

• A type of anemia in which red blood cells in the blood are destroyed earlier than normal (hemolytic anemia)
• Anemia due to low iron
• After certain infections, major surgery or trauma, or allergic reactions
• Cancer
• Certain medicines
• Bone marrow disease called polycythemia vera
• Bone marrow making too many platelets without a known cause (primary thrombocythemia)
• Recent spleen removal

Some people with high platelet counts may be at risk of forming blood clots. Blood clots can lead to serious medical problems

Veins and arteries vary in size so it may be harder to take a blood sample from one person than another.

Other slight risks from having blood drawn may include:

• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)