Tension pneumothorax

Wounds on the chest wall, lungs, bronchi, or esophagus are one-way flaps that communicate with the pleural cavity. The flaps open when inhaled, air enters the pleural cavity, and the flaps close when exhaled. As you breathe, the pressure in the pleural cavity on the injured side keeps increasing, so that it exceeds the atmospheric pressure, forming a tension pneumothorax, also known as pressure pneumothorax or valve pneumothorax.