Thrombocytopenia

A platelet count is a clue that must be interpreted with the patient’s bleeding, thrombosis, illness, medication exposure, other blood-cell lines, blood film, and trend. Thrombocytopenia can result from decreased platelet production, increased destruction or consumption, sequestration, dilution, or in-vitro clumping. The mechanism matters because some patients need confirmation and a focused outpatient evaluation, while others have a time-critical thrombotic or bleeding syndrome. Canadian Blood Services identifies a normal platelet count as 150–400 × 10⁹/L and notes increased risk of spontaneous serious bleeding below 10 × 10⁹/L. These values frame risk but do not replace an assessment of the cause and clinical state. [1] Start by deciding whether the result is real, new, and isolated. Review previous CBCs and the current CBC, examine the peripheral blood film, and look for platelet clumps, schistocytes, blasts, anemia, or leukocyte abnormalities. Ask about bleeding, recent illness, pregnancy, alcohol, liver disease, autoimmune disease, malignancy, transfusion, and every prescribed, non-prescription, and injected medication. Specifically establish recent unfractionated heparin, low-molecular-weight heparin, line-flush, and heparin-coated-device exposure. A stable low count without symptoms is different from a rapidly...