Platelets are formed by fragmentation of bone marrow cells called megakaryocytes. They lack nucleus and have a lifespan of around eight to twelve days. Blood platelets play an important role in stopping bleeding by forming clots. While a low level of platelets in the blood may result in excessive bleeding; high platelet count may cause formation of blood clots, which can block blood vessels and result in heart attacks, stroke and blocked blood vessels in arms and legs. Hence, maintaining a normal platelet count is necessary to avoid such conditions. Platelet count test is included in a complete blood count, and is often required, in case of bleeding disorders or bone marrow diseases.
Normal Platelet Levels
In case of a healthy individual, the normal platelet level ranges between 150,000 and 450,000 per μl (micro liter) of blood. According to statistics, almost 95% of healthy people have platelet values within this range. Though a count which is above or below this range is considered abnormal, some people with small variations are found to be perfectly healthy. However, drastic variations from the normal platelet count can be fatal. Low platelet count (thrombocytopenia) and high platelet count (thrombocytosis) can cause problems in blood coagulation. Functional disorders of the platelets are collectively termed thrombocytopathy.
Even though the normal platelet level of all healthy human beings are said to be within the range of 150,000 and 450,000 per μl (micro liter) of blood, slight variations are considered normal in some people. According to health experts, a value between 150,000 and 450,000 per μl of blood is the normal platelet count in children, whereas in adults, it is between 150,000 and 400,000 per μl of blood. It has also been observed that, people living in high altitudes have an increased platelet count, as compared to their counterparts. This condition can also be found in women after childbirth and those who consume oral contraceptives. Strenuous exercises may also cause a hike in the platelet count. Some women may have a low blood platelet count, just before menstruation. Patients who are undergoing chemotherapy and radiation therapy may also have a low platelet count. Some rare genetic disorders, like Glanzmann's Thrombasthenia, Bernard-Soulier disease and Chediak-Higashi syndrome, may cause defective platelets.
A platelet level which is below 50,000 or above 1,000,000 is considered critical. If the count sinks below 20,000, the condition may cause spontaneous bleeding and is considered life-threatening. In short, drastic variations in the normal platelet count are considered as serious conditions, which have to be addressed at the earliest. In some cases, variations in normal platelet count may indicate underlying diseases. It may also happen that such variations give rise to serious health problems. As such, any variation in platelet count should be brought to the notice of a medical professional immediately.
Disclaimer: This article is for informational purposes only, and should not be used as a replacement for expert medical advice. Visiting your physician is the safest way to diagnose and treat any health condition.