Platelets — Normal Range & Interpretation
Platelets are anucleate cell fragments derived from megakaryocytes that drive primary hemostasis by forming the initial platelet plug at sites of vascular injury. The count reflects both marrow production and peripheral consumption, making it a critical marker of bleeding and clotting risk. Counts below 50,000/μL raise surgical bleeding risk, and counts below 20,000/μL predict spontaneous hemorrhage.
| Male | Female | Unit | Category |
|---|---|---|---|
| 150,000–400,000 | 150,000–400,000 | /μL | CBC / Hematology |
Clinical Context
Platelets are anucleate cell fragments derived from megakaryocytes that drive primary hemostasis by forming the initial platelet plug at sites of vascular injury. The count reflects both marrow production and peripheral consumption, making it a critical marker of bleeding and clotting risk. Counts below 50,000/μL raise surgical bleeding risk, and counts below 20,000/μL predict spontaneous hemorrhage.
Thrombocytopenia results from immune destruction in ITP, consumption in DIC and TTP, sequestration in splenomegaly, marrow suppression from chemotherapy or alcohol, and medication effects from heparin, valproate, and linezolid. Thrombocytosis occurs as a reactive response to infection, iron deficiency, inflammation, malignancy, and post-splenectomy states, or as a primary finding in essential thrombocythemia and other myeloproliferative disorders.
High-yield for NP boards: heparin-induced thrombocytopenia and the need to stop heparin immediately, the classic pentad of TTP, and the contraindication to platelet transfusion in TTP and HIT. Expect questions linking isolated thrombocytopenia with petechiae and mucosal bleeding to ITP in children after a viral illness. Know that iron deficiency anemia presents with reactive thrombocytosis, and that aspirin and NSAIDs impair platelet function without lowering the count, so bleeding occurs despite normal numbers.
Practice Questions
A 40-year-old female presents for a preoperative evaluation before an elective cholecystectomy. Her CBC shows a platelet count of 245,000/μL with no history of bleeding or bruising. Which next step is most appropriate based on this platelet value?
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