How debilitating is a tension pneumothorax?

Can be deadly: Tension pneumothorax occurs when pressure builds up in one side of the chest and collapses the lung. This is rapidly fatal and is treated as an emergency. Once it is released, a tube is left in the chest for a few days. After it is removed, people usually recover completely.

Lethal: If the collapsed lung (pneumothorax) creates enough pressure, it can compress the right side of the heart. This decreases the blood return to the heart. Without adequate blood return, your heart does not have enough blood to pump out to your body. This is called tension pneumothorax. If the pressure is not released, this is rapidly fatal.