Low activated partial thromboplastin time is commonly seen in patients with acute myocardial infarction, pulmonary embolism, cerebrovascular lesions, deep vein thrombosis, nephrotic syndrome, or those who have been taking oral estrogen-based contraceptives for a long time and have a hypercoagulable state in late pregnancy. The abbreviation for activated partial thromboplastin time is APTT, which is an important indicator of coagulation function, reflecting whether the various functions of the endogenous coagulation pathway are normal. The normal value of activated partial thromboplastin time is generally 26-36 seconds, when the indicator is low, it indicates that the body is in a hypercoagulable state, and there is a risk of thromboembolism. In addition, the normal reference range of activated partial thromboplastin time varies depending on the reagents and testing methods used in each hospital. Therefore, it is recommended to listen to the opinion of the physician of the hospital where the test is performed, to evaluate the condition comprehensively, and not to use the medication blindly.