Thrombocytosis

Thrombocytosis is a blood disorder characterised by an abnormally high number of platelets in the bloodstream. Platelets play an essential role in blood clotting and help prevent excessive bleeding after injury. When their levels remain elevated, the risk of abnormal clot formation may increase in some individuals.

Thrombocytosis can be classified as primary (essential) thrombocytosis or secondary (reactive) thrombocytosis. Essential thrombocytosis is a rare bone marrow disorder in which platelet production increases without an obvious underlying cause. It may be associated with genetic changes affecting blood-cell production. Reactive thrombocytosis is more common and can develop in response to infections, inflammation, iron deficiency, blood loss, surgery, or certain cancers.

Many people with thrombocytosis have no noticeable symptoms and are diagnosed through a routine blood test. When symptoms occur, they may include headaches, dizziness, visual disturbances, tingling, chest discomfort, or unusual clotting or bleeding. Diagnosis usually involves a complete blood count and may require additional blood tests, genetic testing, or bone marrow evaluation.

Treatment depends on the underlying cause and the individual's risk of complications. Reactive thrombocytosis often improves when the underlying condition is treated. Essential thrombocytosis may require medicines that reduce platelet production or lower the risk of blood clots. Regular medical monitoring is important for appropriate management.