A bruise on the hands and feet means that there is bleeding under the skin of the hands and feet, which means that blood is leaking from inside the blood vessels to outside the vessels, causing the skin of the hands and feet to bruise. Bruising of the skin of the hands and feet can be seen in a variety of diseases. The first condition is vitamin C deficiency, also known as scurvy. In this patient, due to vitamin C deficiency, capillary permeability increases and density decreases, resulting in bruising of the hands and feet, which will improve significantly when treated with vitamin C supplementation. In order to prevent vitamin C deficiency, it is necessary to eat more fresh fruits and vegetables in daily life. The second condition is coagulation disorders, such as hemophilia, vitamin K deficiency, and disseminated intravascular coagulation. Due to decreased coagulation factor activity and clotting dysfunction, bruising of the hands and feet can also occur. Patients with bruised hands and feet need to be seen by a hematologist in a timely manner to test the number of platelets and the function of coagulation factors, as well as to check the function of capillaries to find the cause and give appropriate treatment.