Pneumothorax

A pneumothorax is a collection of air in the pleural space between the lung and the chest wall. Symptoms typically include the sudden onset of sharp, one-sided chest pain and shortness of breath. In a minority of cases a one-way valve forms from an area of damaged tissue, raising the air pressure in the space between the chest wall and the lungs to what has historically been called a tension pneumothorax, which can cause a steadily worsening oxygen shortage and low blood pressure leading to potentially fatal obstructive shock unless reversed. It is often called a collapsed lung, though that term can also refer to a related but distinct condition called atelectasis.