Children’s feet bruises for no reason, may be traumatized, allergic purpura, aplastic anemia and other factors. 1. Trauma: If a child’s foot is bumped or hit, it will cause inflammatory oozing from the local blood vessels and soft tissues, thus causing the symptom of unexplained foot bruising. 2. Anaphylactic purpura: If a child is exposed to allergens, such as pollen, animal feathers, dust, etc., it will cause the body to produce a metamorphic reaction, which will cause the local capillary permeability to increase, so that the local skin, blood vessels, inflammation and bleeding, and the symptom of unexplained bruising of the feet will occur. 3. Aplastic anemia: If a child suffers from aplastic anemia, it will lead to local platelet reduction or abnormality, which will make the child’s foot hemostatic function decline, causing the symptoms of unexplained foot bruising. Children’s feet bruises for no reason, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, give targeted treatment or treatment.