Why am I having this test?

• If you have symptoms that may be related to excess bleeding or delayed blood clotting, such as:
  • A rash of pinprick-sized red and purple dots on the skin (petechiae). These are small collections of blood (hemorrhages) in the skin.
  • Heavy menstrual bleeding.
• To help monitor treatment for:
  • Thrombocytopenia. This is a condition in which you have a low platelet count.
  • Bone marrow failure.

What is being tested?

This test measures how many platelets you have within a specific amount (volume) of blood.

What kind of sample is taken?

A blood sample is required for this test. It is usually collected by inserting a needle into a blood vessel or by sticking a finger with a small needle.

Tell a health care provider about:

• Any allergies you have.
• All medicines you are taking, including vitamins, herbs, eye drops, creams, and over-the-counter medicines.
• Any blood disorders you have.
• Any surgeries you have had.
• Any medical conditions you have.
• Whether you are pregnant or may be pregnant.

How are the results reported?

Your test results will be reported as a value that indicates how many platelets are in the blood volume. This will be given as platelets per cubic millimeter (mm³) of blood.

• Adult or elderly: 150,000–400,000/mm³.
• Child: 150,000–400,000/mm³.
• Infant: 200,000–475,000/mm³.
• Premature infant: 100,000–300,000/mm³.
• Newborn: 150,000–300,000/mm³.

What do the results mean?

A result that is within your reference range is considered normal, meaning that you have a normal amount of platelets in your blood.

• Certain types of cancer, such as leukemia or lymphoma.
• A condition in which the bone marrow produces excess amounts of all cell types, including platelets (polycythemia vera).
• A condition that can occur after surgery to remove the spleen (post-splenectomy syndrome).
• Rheumatoid arthritis.
• Anemia due to lack of iron (iron-deficiency anemia).

• A condition in which the spleen breaks down platelets faster than normal (hypersplenism).
• A hemorrhage somewhere in your body.
• Low platelet count due to your body's disease-fighting system attacking your platelets (immune thrombocytopenia).
• Cancer. Chemotherapy treatments for cancers such as leukemia can also cause low platelet count.
• A rare, serious form of thrombocytopenia that causes blood clots (thrombotic thrombocytopenia).
• HELLP syndrome, a disorder of pregnancy that causes high blood pressure and other serious problems.
• Certain disorders that are passed from parent to child (inherited) that cause a low platelet count.
• A condition in which the proteins that control blood clotting are overactive, causing abnormal clotting processes to occur (disseminated intravascular coagulation, DIC).
• A disease that causes long-term inflammation and pain in many parts of the body (systemic lupus erythematosus, SLE).
• Certain types of anemia, such as pernicious anemia or hemolytic anemia.
• Infection.

Talk with your health care provider about what your results mean.

Questions to ask your health care provider

• When will my results be ready?
• How will I get my results?
• What are my treatment options?
• What other tests do I need?
• What are my next steps?

Summary

• Platelets are specialized cells that help the blood clot. When you get a tissue injury like a cut, platelets gather at the site of the injury to stop the bleeding.
• This test measures how many platelets you have within a specific amount (volume) of blood.
• Talk with your health care provider about what your results mean.