Heparin Induced Throbocytopenia (HIT)

Your Path

  • Heparin induced throbocytopenia (HIT)


  • Antibody mediated platelet destruction that leads to thrombocytopenia and prothrombotic state

Risk Factors

  • Typically 50% decline w/in 5-10d of treatment with heparin; or < 1 d if prior exposure to heparin


  • Thrombocytopenia associated with arterial and/or venous thrombosis (e.g. skin necrosis, DVT, unexplained arterial thrombosis), adrenal hemorrhage, anaphylactic-type reaction after IV heparin infusion
  • 4Ts score (link below) can help w/diagnosis

Physical Exam Findings

  • DVT or arterial thrombotic events that occur linked to use of heparin and are otherwise unexplained