Hemopneumothorax, or haemopneumothorax, is the condition of having both air (pneumothorax) and blood (hemothorax) in the chest cavity.

This fluid holds the two membranes together by surface tension, as much as a drop of water between two sheets of glass prevents them from separating.

Other diagnostic tests may also be performed to further evaluate the fluid in around the lungs, for instance a chest CT scan or an ultrasound.

Treatment for this condition is the same as for hemothorax and pneumothorax independently: by tube thoracostomy, the insertion of a chest drain through an incision made between the ribs, into the intercostal space.

A chest tube must be inserted to drain blood and air from the pleural space so it can return to a state of negative pressure and function normally.