Skin easily bruised with external stimulation, thrombocytopenic purpura, leukemia and other diseases caused by blood clotting dysfunction and caused. 1. External stimulation: with age, blood vessel elasticity will become worse, brittleness becomes bigger, so slightly stimulated by external force, the skin is easy to bruise. 2. Thrombocytopenic purpura: the occurrence of this disease is related to heredity, immune dysfunction and other reasons, but also secondary to bone marrow transplantation, systemic lupus erythematosus and other diseases. It is mainly manifested as ecchymosis and petechiae on the skin and mucous membranes, so the skin of patients is easy to bruise. 3. Leukemia: the cause of this disease is still unclear, research shows that it may be related to gene mutation, heredity, abnormal immune function, viral infection, ionizing radiation, bad habits, multiple myeloma and other reasons. In the early stages of the disease, patients may experience ecchymosis of the skin, which can manifest as easy bruising of the skin. Patients may also have anemia, fever, bleeding gums and other symptoms. It is recommended that people with easily bruised skin go to the hospital in time to complete the relevant examinations to clarify the specific cause.