Bruising and bleeding at the touch of the hand may be due to abnormalities of the blood vessel wall, abnormal platelet index, abnormal coagulation function, anti-coagulation and fibrinolytic abnormalities. 1. Vascular wall abnormalities: can be divided into congenital and acquired abnormalities, the former includes hereditary hemorrhagic capillary dilatation, familial purpura simplex, etc.; the latter includes sepsis, purpura anaphylaxis, vitamin C deficiency, etc. 2. Platelet abnormality: including quantity abnormality and quality abnormality, the former commonly includes aplastic anemia, leukemia, immune thrombocytopenia, etc.; the latter includes platelet apoplexy, etc. 3. Coagulation abnormalities: including hemophilia, hereditary coagulation factor deficiency, vitamin K deficiency and so on. 4. Anticoagulation and fibrinolytic abnormalities: mostly acquired diseases, such as overdose of heparin and warfarin, or snakebite. There are many conditions that can cause bleeding when hands are touched, if such a situation occurs, please consult a doctor in time, diagnosis and treatment under the guidance of a physician.