This document describes different types of wounds, bleeding, and first aid procedures. It discusses external bleeding which can often be controlled through direct pressure, elevation, and immobilization of the wound. Internal bleeding is more difficult to detect but signs may include paleness, pain, and changes in vital signs. First aid for internal bleeding focuses on maintaining ABCs (airway, breathing, circulation) and seeking medical help. A tourniquet should only be used as an absolute last resort for life-threatening bleeding not controllable by other means.