When you are injured in the field, you are prone to trauma, which is a cut or abrasion. If the injury is not serious, you can not hard to dry the blood on the wound. Because the blood itself has a sterilizing effect, you can let it bleed slightly to disinfect the wound. As long as the wound is elevated, resting on a position higher than the heart, after a few minutes, the bleeding will naturally stop. If the bleeding keeps flowing, it means that the larger blood vessels are injured. At this point, an emergency dressing is needed to stop the bleeding in the affected area. This method of compressing the blood is most effective for minor trauma. However, it can cause hemorrhage if more serious injuries are sustained. For example, a wound with bright red blood (arterial blood) spurting out continuously is not easy to stop bleeding by compression alone. For small wounds in general, after stopping the bleeding, careful disinfection is necessary to prevent bacterial infection. Therefore, disinfectant iodine, antibiotic ointment, clean gauze, bandages and band-aids must always be carried with you. The average adult has 6.25 liters of blood per person involved in blood circulation. A loss of 0.5 liters of blood will cause only slight dizziness, a loss of 1 liter of blood causes deficiency – increased heart rate and whistling rate, a loss of 1.5 liters of blood will cause collapse, and more than 2.24 liters will cause death, and decisive steps should be taken immediately to stop the bleeding. In small amounts of blood loss, the total volume of blood is maintained in balance with the replenishment of body fluids – perhaps resulting in a slight anemia, but not serious. Body fluids need to be replenished by drinking water. Blood carries oxygen necessary for vital activity. When a whistling pause is accompanied by bleeding, rescue measures should be taken separately and simultaneously, both to enable the patient to resume whistling as soon as possible and to be able to stop the bleeding as soon as possible. In the case of venous or capillary bleeding, the bleeding can be stopped by simple compression. Micro-arterial bleeding can be stopped by dressing the wound site with or without removal of clothing. In severe injuries, pressure bandaging can be applied. Many emergency methods can be used to stop bleeding. Handkerchiefs and smock cloths can be used for dressing – clean dressing materials should be chosen whenever possible, and the dressing should be completed quickly. Bandage materials carry pathogenic bacteria that can cause the risk of infection. However, if the situation is very urgent, it is not possible to consider whether the dressing material has been sterilized. Applying continuous pressure around the wound site for 5-10 minutes may stop bleeding. It is ideal to resist the urge to resist the urge to loosen and look at it to stop the bleeding. Your medical kit should also come with skim cotton. Tightening with a bandage will maintain the constant pressure needed.