Due to the explosion of high-pressure boilers, chemicals or gas, during wartime, due to high explosives or nuclear explosions, huge energy can be released instantly, causing the pressure and temperature at the center of the explosion to increase sharply and spread rapidly to the surroundings, thus forming a supersonic high-pressure wave, namely a shock wave. The continuous overpressure-negative pressure of air shock waves or underwater shock waves acts on the human body, causing the chest and abdomen to compress and expand sharply, causing a series of hemodynamic changes, causing damage to the heart, lungs and blood vessels; the gas in the body produces an implosion effect under the action of overpressure-negative pressure, causing damage to gas-containing tissues (such as alveoli); when the pressure wave passes through tissues of different densities, it is reflected on the interface and causes a fragmentation effect, causing damage; and when tissues of different densities are affected by the same pressure wave, the speed is different due to different inertia, and tearing and bleeding occur at the connection site. The above injuries caused by the direct action of the shock wave itself on the human body are called blast injuries.