A bruise on the body means that there is a local bleeding condition, that is, blood flowing from inside the blood vessels to outside the blood vessels. The most common causes of cyanosis are as follows: 1. trauma, such as collision after the capillary rupture bleeding, resulting in cyanosis. 2. platelet reduction, such as immune thrombocytopenia, platelet reduction after the body’s hemostatic function will decline, will also appear on the body cyanosis. 3. coagulation abnormalities caused by common hemophilia A, hemophilia B, vascular hemophilia, etc., due to