Hemopneumothorax, or haemopneumothorax, is a medical term describing the combination of two conditions: pneumothorax, or air in the chest cavity, and hemothorax (also called hæmothorax), or blood in the chest cavity.

A hemopneumothorax often happens after high speed crashes and penetrating chest wounds.

The blood and air cause the lung to collapse (i.e. catamenial hemopneumothorax).

The accumulation of blood in the thoracic cavity (hemothorax) exacerbates the problem, creating a hemopneumothorax.

Spontaneous Hemopneumothorax.

Small amounts of fluid may be noted on the chest X-ray (hydropneumothorax); this may be blood (hemopneumothorax).

A lesion in one of her lungs had ruptured, filling her chest cavity with blood and air (a condition known as hemopneumothorax) and leaving her near death.

Catamenial pneumothorax is the most common form of thoracic endometriosis syndrome, which also includes catamenial hemothorax, catamenial hemoptysis, catamenial hemopneumothorax and endometriosis lung nodules, as well as some exceptional presentations.