Thrombocytosis is present, if the platelet count is elevated to over x 109/L. A distinction is made between reactive and neoplastic (myeloproliferative) thrombocytosis.


Clinical picture:
Reactive thrombocytosis is rarely associated with platelets counts over 1,000 x 109/L. If no additional risk factors for thromboembolism are present, reactive thrombocytosis does not normally lead to thrombosis. The highest values (over 3,000 x 109/L) are observed in essential thrombocythemia (myeloproliferative neoplasms). This can be associated with an increase in bleeding and thrombotic complications.


- Hemorrhage
- Trauma
- Post-operative
- Chronic iron deficiency
- Initially after splenectomy
- Solid tumors
- Chronic infections
- Connective tissue diseases
In myeloproliferative neoplasms, especially in essential thrombocythemia