A high activated partial thromboplastin time, i.e., prolonged APTT, indicates a disorder of coagulation and a tendency to bleed. It may be related to taking drugs, blood system diseases, liver diseases and immune system diseases. 1. Taking drugs: if patients use warfarin, heparin and other drugs for a long time, they can inhibit the synthesis of coagulation factors, which will lead to high activated partial thromboplastin time. 2. Blood system diseases: For example, hemophilia patients with deficiency of coagulation factor VIII or coagulation factor IX can also lead to high activated partial thromboplastin time and bleeding. 3. Liver diseases: most of the clotting factors are synthesized in the liver. When patients suffer from liver diseases such as hepatitis and cirrhosis, there may be a decrease in the synthesis of clotting factors, which affects the coagulation function, thus resulting in a high activated partial thromboplastin time. 4. In addition, patients with systemic lupus erythematosus, disseminated intravascular coagulation, transfusion of large quantities of stored blood, etc. can also make the activated partial thromboplastin time is high. Warm reminder: activated partial thromboplastin time is high in patients, considering the possible coagulation dysfunction, it is recommended that patients go to the hospital in a timely manner, identify the cause of the disease, and then treated under the guidance of the doctor.