How to Count Platelets

Platelets are small, oddly-shaped structures that float in your blood. When you are injured from a cut or internal bleeding platelets are first on the scene to make tissue repairs. They are the main agents responsible for the formation of scabs and bruises, both of which are created to thicken blood from spewing outside of blood vessels. Platelets, along with many other blood structures, are often counted during blood tests. They are measured in parts per microliter.

Instructions

• 1

  Order a CBC, or complete blood count, test. Platelets are almost always counted during these types of blood tests. They are most often ordered during annual visits with a physician or if your doctor suspects you are ill. Many doctors will also recommend a complete blood count test if they think you have a bone marrow disease such as leukemia or a bleeding disorder. Symptoms of bleeding disorders include unexplained bruising or exceptionally long healing times for minor cuts and scrapes.

• 2

  Prepare for the test. After you have the date of your blood test, mark it down on your calendar. There is nothing major you have to do to prepare for the test. However, before your appointment, it is essential that you inform your doctor of any changes in medication. The addition of certain drugs, such as those used for chemotherapy, can skew your platelet counts. By warning your doctor, he is prepared for low platelet counts. Other drugs such as indomethacin and quinidine can affect your platelet count.

• 3

  Give blood. Blood tests are done to patients every day and are not anything to cause worry. The nurse or doctor taking your blood has probably done countless blood tests and is prepared for yours as well. During a blood test, a small amount of blood is taken from your body. The person drawing your blood will first dab the area with antiseptic, a germ-killing solution, to ensure you are not infected with an antigen. A small needle, attached to a vial, is inserted into the target area. Usually, blood is drawn from veins located at the inside of your elbow or on the backside of your hand. Pressure from your blood vessels will force blood into the needle and eventually to the vial. Once enough blood is collected, the needle is removed and you are given a bandage for the puncture site.

• 4

  Wait for your results and then analyze them. Once your blood is drawn, it is sent to a lab for testing. Many labs use a machine called a hemocytometer. It uses light to determine platelet size and concentration. After testing, the lab will give you your results. Your test results include vast amounts of data. Besides platelet count, your results will have counts for white blood cells, red blood cells and hemoglobin. Platelet results are displayed by number of platelets per microliter, mcL, units. Normal values for platelets range between 150,000 and 400,000 platelets per mcL. If your platelet count is outside of this range, you do not necessarily have an irregular platelet count. Normal ranges vary among blood labs. Once your doctor sees your results, he is able to assess whether your platelet count is abnormal.