A<unk>  is a collection of blood within the tissue of the lung. It may result when a<unk>  laceration fills with blood. A lung laceration filled with air is called a pneumatocele. In some cases, both pneumatoceles and<unk> s exist in the same injured lung.<unk> s take longer to heal than simple pneumatoceles and commonly leave the lungs scarred. A<unk>  contusion is another cause of bleeding within the lung tissue, but these result from microhemorrhages, multiple small bleeds, and the bleeding is not a discrete mass but rather occurs within the lung tissue. An indication of more severe damage to the lung than<unk>  contusion, a<unk>  also takes longer to clear. Unlike contusions,<unk> s do not usually interfere with gas exchange in the lung, but they do increase the risk of infection and abscess formation.
Pulmonary hematoma
Hemothorax
Chylothorax
Urinothorax
Pneumothorax ex vacuo
Hemopneumothorax
Hydropneumothorax
Pneumothorax