The Cardiovascular System - Platelets

Publication Date: 
Tue, 12/01/2015
By: Alere Staff

Platelets are the smallest component of our blood, but they play a huge role in our health. Their job is to form blood clots at the site of an injury in order to stop the bleeding. If we are hurt, our platelets will bind to the injured tissue or blood vessel and create the clot that will stop the bleeding. Platelets are created in our bone marrow before they move to our bloodstream.

Platelet Count

A normal platelet count is within the range of 150,000 and 450,000. When your doctor orders a CBC or “complete blood count”, this is the test that will show them your platelet count. If it is too low, this is known as thrombocytopenia. If it is too high, this is called thrombocytosis.

Thrombocytopenia can be caused by a number of things, including medication you may be taking. Certain types of cancers and chemotherapy are causes as well as genetics and consuming too much alcohol. Finally, if you have a really bad kidney infection or kidney dysfunction, thrombocytopenia can also occur.

Recognizing whether or not you have thrombocytopenia is where it gets a little tricky. The symptoms of thrombocytopenia are not unlike the symptoms of a high INR. These include bruising easily and frequent bleeding from the gums, nose or gastrointestinal tract (GI bleed). If you experience any of these symptoms, ask your doctor to check your blood count as well as your INR.

It’s a bit of the same regarding thrombocytosis. When your platelets are too high, you are at risk of developing clots predominantly in your arms and legs. The only known causes of thrombocytosis are anemia, cancer, inflammation and some infections.

If you have questions regarding these conditions or about platelet function, ask your doctor about the relation between your INR and your platelet count.

Interested in learning more? Check out these other articles on The Cardiovascular System:


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  2. Mayo Clinic Staff. Diseases and Conditions: Thrombocytopenia (Low Platelet Count). Mayo Clinic. March 31, 2015.  Retrieved from website:
  3. Yi-Bin Chen, MD. Platelet Count. Medline Plus. January 27, 2015. Retrieved from website:
  4. American Red Cross. Platelets. Retrieved November 16, 2015 from the website: