Hemothorax

A hemothorax (derived from hemo- [blood] + thorax [chest], plural hemothoraces) is an accumulation of blood within the pleural cavity. The symptoms of a hemothorax may include chest pain and difficulty breathing, while the clinical signs may include reduced breath sounds on the affected side and a rapid heart rate. Hemothoraces are usually caused by an injury, but they may occur spontaneously due to cancer invading the pleural cavity, as a result of a blood clotting disorder, as an unusual manifestation of endometriosis, in response to pneumothorax, or rarely in association with other conditions.

Hemothoraces are usually diagnosed using a chest X-ray, but they can be identified using other forms of imaging including ultrasound, a CT scan, or an MRI. They can be differentiated from other forms of fluid within the pleural cavity by analysing a sample of the fluid, and are defined as having a hematocrit of greater than 50% that of the person's blood. Hemothoraces may be treated by draining the blood using a chest tube. Surgery may be required if the bleeding continues. If treated, the prognosis is usually good. Complications of a hemothorax include infection within the pleural cavity and the formation of scar tissue.