When there are too many platelets in the blood, this is referred to as thrombocytosis.
A normalplatelet countis 150,000 to 450,000 platelets per microliter (mcL) of blood.
A diagnosis of thrombocytosis is made when platelets are higher than 450,000 per mcL.
Yoshiyoshi Hirokawa / Getty Images
This article discusses the types, symptoms, causes, and diagnosis of thrombocytosis.
However, it is possible that some symptoms may be present.
This is also referred to as essential thrombocythemia, or ET.
The bone marrow may not function normally due to a genetic mutation.
A mutation in theCALRgene can also cause too many platelets to be made in the bone marrow.
This lab test would demonstrate a platelet count above 450,000 per mcL.
These may provide some indication as to the cause of elevated platelets.
Frequently Asked Questions
What can cause a high platelet count in children?
The most common cause of high platelets in children is an infection.
It is much less likely to be resulting from a primary bone marrow disorder.
What is essential thrombocytosis?
What is reactive thrombocytosis?
Reactive thrombocytosis is an elevation in platelet counts for a reason outside of the bone marrow.
Remember that the most common cause of high platelets is due to a reactive process.
Johns Hopkins Medicine.What are platelets and why are they important?
National Heart, Lung, and Blood Institute.Thrombocythemia and thrombocytosis.
Briere JB.Essential thrombocythemia.Orphanet J Rare Dis.
2007;2(1):3. doi:10.1186/1750-1172-2-3
National Organization for Rare Disorders.Essential thrombocythemia.
2019;69(684):e462-e469.
doi:10.3399/bjgp19X704309
Kucine N, Chastain KM, Mahler MB, Bussel JB.Primary thrombocytosis in children.Haematologica.
2020;95(12):1599-1613. doi:10.1002/ajh.26008
