What Are Platelets a Measure Of?

Platelets are the element in blood that causes clotting. A normal platelet count is between 150,000 and 450,000 platelets per microliter of blood. This number can be effected by several conditions. A platelet count is used to gather information about the general wellness of a patient's blood. A number of conditions can cause lower platelet counts, and doctors must compare the results of a platelet count with the patient's other symptoms.

Blood Clotting Agents

• Platelets cause scabs to form as they stick together.

  Platelets are the agent responsible for blood clotting. Clotting is a reaction to open wounds to prevent further blood loss. A scab on a small cut is a concentrated collection of platelets. The body is constantly creating new platelets in the bone marrow. Clotting is also the reaction responsible for heart attacks. When the platelets get caught on cholesterol in the arteries, they can block the flow of blood to vital organs.

Lowered Platelet Counts

• This is a microscopic view of bone marrow which doctors would use to diagnose bone marrow cancer.

  There are a number of conditions which cause lowered platelet counts. For example, a person who has recently lost a significant amount of blood will have a lower platelet count. Hemophilia is a genetic disease whose sufferers experience platelets which do not function correctly. A less well known, but more prevalent genetic cause of low platelet counts is von Willebrand disease which exhibits similar symptoms to Hemophilia, but is caused by a slight different genetic deficiency. When no genetic disease is present, doctors may suspect leukemia or another bone marrow cancer as the culprit of low platelet counts.

Symptoms of Low Platelet Count

• A typical platelet count will be conducted by having blood drawn from a vein.

  A low platelet count is dangerous because it can cause uncontrollable bleeding. Any platelet count below 20,000 platelets per microliter of blood is considered life threatening as it may cause spontaneous bleeding. In addition to spontaneous bleeding, unexplained bruising is a common symptom of a low platelet count. Any situation in which the blood seems to be taking an unusually long time to clot, such as bleeding for an extended period of time from a small injury, may be a symptom of an abnormal platelet count.

Other Causes of Low Platelet Count

• Doctors may prescribe drugs to lower platelet counts or recommend against certain drugs like aspirin before a major surgery.

  Besides the worst case scenarios of cancer of genetic diseases, prolonged bleeding, such as a bleeding stomach ulcer, may be a hidden cause of a lowered platelet count. Persons with autoimmune disorders such as lupus may exhibit low platelet counts. Certain drugs also may induce lower platelet counts. Some drugs called "blood thinning agents," like nitroglycerin, are intentionally used to lower platelet counts in hopes of preventing a heart attack. Other drugs, such as acetaminophen and chemotherapy drugs, can lower platelet counts in patients.