Heparin-induced thrombocytopenia, unspecified

This code represents a decrease in platelet count caused by an immune reaction to heparin administration, where the specific type of heparin-induced thrombocytopenia (HIT) is not documented. It signifies a serious, immune-mediated adverse drug reaction that can lead to thrombotic complications.

Use this code when the medical record clearly indicates a diagnosis of heparin-induced thrombocytopenia, but the provider has not specified whether it is Type I (non-immune) or Type II (immune-mediated). Documentation should include evidence of recent heparin exposure and a significant drop in platelet count.

• Always query the provider for clarification on the type of HIT (Type I vs. Type II) if not specified, as Type II (D75.821) has different clinical implications.
• Sequence this code as a principal diagnosis when HIT is the reason for admission or the primary condition being treated.
• Do not confuse this with other forms of thrombocytopenia not induced by heparin; ensure a clear causal link to heparin is documented.