High activated partial thromboplastin time may be caused by hemophilia, liver cirrhosis, disseminated intravascular coagulation and so on. 1. Hemophilia: Hemophilia is a bleeding disorder caused by hereditary prothrombin generation disorder, and patients will have bleeding and hematoma formation. When hemophiliacs undergo prothrombin test, there will be prolongation of activated partial thromboplastin time. 2. Cirrhosis: prothrombin time test for cirrhotic patients can determine the liver reserve function and prognosis. If cirrhosis is in advanced stage or hepatocyte damage is serious, activated partial thromboplastin time will be high when liver prothrombin activity test is performed. 3. Disseminated intravascular coagulation: Disseminated intravascular coagulation may be caused by malignant tumor, serious infection, amniotic fluid embolism and other diseases. When the patient has disseminated intravascular coagulation, plasma coagulation factor examination will show prolonged activated partial thromboplastin time. 4. Others: Patients with high activated partial thromboplastin time may also be considered to have vitamin K deficiency or heparin therapy. It is recommended that patients with high activated partial thromboplastin time need to consult a doctor in time for examination, and the doctor will choose appropriate measures for treatment after clarifying the cause of the disease.