What are platelets? Also referred to as thrombocytes, they are a one of the cell types that make up your blood, the others being red blood cells and white blood cells. All of which are suspended in a liquid called plasma.
A platelet is a very small fragment of a large cell that’s produced in your bone marrow and each one has a life span of about 10 days. Platelets are the smallest and lightest of all blood cells.
Th primary function of a platelet is to stop blood from escaping out through a hole in a blood vessel, what’s commonly referred to as bleeding. Platelets contain specialized chemicals that become sticky when activated, which allows them to adhere to a blood vessel and causes your blood to clump at the site of an injury. This blood clotting action seals the opening, thus preventing an excessive loss of blood.
For a variety of reasons, blood clots can form within your blood vessels in the absence of vessel wall injury. An example is at the site of vessel plaque build up. This activity is undesirable because it can potentially obstruct blood flow. An important part of this process is platelets. Aspirin reduces platelet stickiness by a blocking the production of a prostaglandin, thus the likelihood of them clumping together is reduced as well. This anti-clotting benefit of aspirin is why it’s sometimes recommended to lower your risk of a heart attack and ischemic stroke. And von Willebrand’s disease, a clotting disorder, likewise reduces the ability of blood to clot, just for a different reason.
A blood platelet count is a test that measures how many platelets are present in a microliter of your blood. A normal blood platelet count falls somewhere between 150,000 and 400,000, although these numbers may differ slightly among laboratories. Platelet counts are generally included as part of a complete blood count. It’s sometimes ordered in isolation to monitor or diagnose diseases, particularly if you have symptoms of unexplained bruising or excessive wound bleeding.
If your blood platelet count is higher than normal the health condition is known as thrombocytosis. Many experience no problems from a high amount of platelets, although your risk for blood clots increases and some have a myeloproliferative disorder. Causes for your high platelet count may be:
- spleen removal
- polycythemia vera
- living at high altitude
- chronic myelogenous leukemia
- certain drugs ~ estrogen, oral contraceptives
On the flip side, a low platelet count is called thrombocytopenia. There are a variety of lower than normal platelet count causes, a few them are:
- celiac disease
- blood transfusion
- hemolytic anemia
- viral infection ~ HIV
- vitamin K deficiency
- prosthetic heart valve
- just before menstruation
- thrombocytopenic purpura
- chemical exposure, toxins
- overactive, enlarged spleen
- hemolytic uremic syndrome
- excessive alcohol consumption
- chronic bleeding ~ stomach ulcer
- chemotherapy, radiation cancer treatment
- autoimmune disorder ~ lupus, rheumatoid arthritis
Additionally, certain drugs can cause immune system confusion, which can lead to platelet destruction, e.g. heparin, quinidine, sulfa drugs, anticonvulsants, acetaminophen, digoxin, valium, and nitroglycerin.