Subcutaneous bleeding is more commonly characterized as petechiae, purpura, ecchymosis or hematomas. The main cause of subcutaneous hemorrhage is damage to the walls of the blood vessels, causing blood to leak out of the vessels to the outside. Depending on the size of the subcutaneous hemorrhage, it can be categorized as petechiae less than 2 mm, purpura 3-5 mm, petechiae greater than 5 mm, or hematomas that are significantly elevated above the skin. For mild, unbroken subcutaneous hemorrhage, patients can use cold compresses, and then switch to hot compresses after 48 hours. When the surface of the subcutaneous hematoma breaks down or is accompanied by a large hematoma, it is recommended to go to the hospital for treatment. If the subcutaneous hemorrhage site is located in the lower limbs, minimize walking and take more rest to avoid secondary injuries. Excluding the daily bumping situation, subcutaneous hematoma appears on the skin by itself, the patient needs to go to the local hospital for examination and treatment in a timely manner, so as to avoid delaying the condition.