In combat, what is the biggest threat to a casualty's life?

• A. Infection
• B. Hypothermia
• C. Bleeding
• D. Shock

Answer: (C)

Bleeding is the biggest threat to life because uncontrolled blood loss can kill within minutes. The body can survive many injuries, but as circulating blood drops, oxygen delivery to organs plummets and organ function fails rapidly. Stopping the bleed has the greatest impact on survival, and the immediate focus is hemorrhage control—direct pressure, wound packing, and, if necessary, a tourniquet placed correctly above the wound. Infection and hypothermia are serious risks, but they tend to cause harm over a longer timescale and don’t kill as quickly as massive bleeding if it’s not addressed first. Shock is a dangerous consequence of severe blood loss, so preventing and treating bleeding effectively also helps prevent progression to shock.