Thrombocytopenia

Thrombocytopenia
Other names	Thrombocytopaenia, thrombopenia
A photomicrograph of the blood showing thrombocytopenia
Specialty	Hematology
Causes	Bone marrow not making enough platelets, body destroying platelets, spleen holding too many platelets[1]
Diagnostic method	Complete blood count[1]
Treatment	None, immunosuppressants, platelet transfusion, surgical removal of the spleen[1]

In hematology, thrombocytopenia is a condition characterized by abnormally low levels of platelets (also known as thrombocytes) in the blood.^[2] Low levels of platelets in turn may lead to prolonged or excessive bleeding. It is the most common coagulation disorder among intensive care patients and is seen in a fifth of medical patients and a third of surgical patients.^[3]

A normal human platelet count ranges from 150,000 to 450,000 platelets/microliter (μL) of blood.^[4] Values outside this range do not necessarily indicate disease. One common definition of thrombocytopenia requiring emergency treatment is a platelet count below 50,000/μL.^[5] Thrombocytopenia can be contrasted with the conditions associated with an abnormally high level of platelets in the blood – thrombocythemia (when the cause is unknown), and thrombocytosis (when the cause is known).^[6][7]