A high APTT suggests an abnormality in the endogenous coagulation pathway, which may be due to coagulation factor deficiency disorders (e.g., hemophilia A, hemophilia B) or to sodium heparin overdose. APTT is the acronym for partially activated prothrombin time, an indicator of whether the endogenous coagulation pathway is normal. Coagulation factors involved in the endogenous coagulation pathway include VIII, IX, XI, XII, etc. Deficiencies in these coagulation factors can lead to high partial activated plasminogen time, such as hemophilia A (coagulation factor VIII deficiency) and hemophilia B (coagulation factor IX deficiency). Anticoagulant drugs such as sodium heparin and low molecular heparin sodium can cause prolongation of the partially activated plasminogen time, and the dosage of sodium heparin or low molecular heparin sodium can be adjusted clinically by monitoring this index. In addition, coagulation factors are mostly synthesized in the liver, and when patients develop severe liver diseases (e.g., severe hepatitis, hepatocellular carcinoma, etc.) resulting in impaired coagulation factor synthesis, it may also lead to high partial activated plasminogen time. It is recommended that patients with high partial activated plasminogen time should consult the hematology department in time, and after the cause of the disease is clarified, the patient should be actively treated for the cause of the disease, and if necessary, the patient should be treated with infusion of cold precipitation, fresh plasma or coagulation factors.