A high mean platelet volume (MPV) reading indicates that a person's blood platelets are of a higher than normal level. Doctors perform the MPV as part of a complete blood count (CBC).
Doctors prescribe the MPV to analyze the number of platelets in a person's bloodstream. Platelets, also called thrombocytes, measure the blood's ability to congeal, or form clots. By taking a platelet count, doctors can understand how well a person's blood clots as it is supposed to. Blood tests can also reveal the presence of underlying diseases and conditions that might need treatment.
Blood Platelet Testing
Platelets are a part of normal blood function. They are round cells made of spongy material that helps blood form clots. Platelets are produced in bone marrow. At any given time, most platelets are traveling throughout the bloodstream. They live for a short time period that averages seven days. The human body is quite precise when it comes to regulating the circulatory system. Therefore, abnormalities in blood platelet production, which can mean unusually high or low volumes of production, can indicate the presence of an underlying condition. A high MPV reading means that bone marrow is producing blood platelets at a higher rate than normal. A high MPV also indicates that blood platelets are of a higher than normal size, which might signal the presence of a disorder.
What Abnormal Platelet Counts Mean
A physician might administer a blood test as part of a routine physical exam or when a patient complains of other symptoms that may indicate a blood disorder. The test is administered by taking a small blood sample, which is usually drawn from a patient's arm via a needle stick. In addition to platelet size, the blood platelet count measures platelet distribution width, or PDW. Physicians analyze blood test results to determine whether or not blood platelet levels are at, above or below the normal level. For each microliter of blood, the average number of platelets falls between 150,000 and 450,000. A number below the 150,000 indicates a person is producing fewer blood platelets than normal. Having less than 50,000 circulating blood platelets may cause minor bleeding problems, while people with less than 20,000 blood platelets can experience more serious bleeding. Conversely, having a blood platelet count in excess of 450,000 might mean that blood clots too easily. A high MPV can be caused by lymphoma, leukemia and Hodgkin's disease. Infections, anemia and inflammatory diseases can also cause an abnormally high MPV reading.
Sometimes, external factors can affect the results of a blood platelet test to show abnormal readings. Strenuous exercise performed before the test can cause an abnormally high MPV level, as can living at a high altitude. Prescription medicines, dietary supplements and herbs might also skew blood test results. Women should notify their healthcare providers if they are pregnant, menstruating or taking birth control pills, as any of those factors can make blood platelet counts appear lower than normal. All individuals, regardless of gender, should inform their healthcare providers of any prescription and non-prescription drugs they are taking, including illicit drugs. Drug use, regardless of whether or not it is authorized, can affect blood tests.
If blood tests come back positive for a higher MPV level than normal, doctors usually prescribe a follow-up test to diagnose or rule out underlying conditions.