Merck Manual

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Thomas G. Weiser

, MD, MPH, Stanford University School of Medicine

Reviewed/Revised Apr 2022 | Modified Sep 2022
Topic Resources

Hemothorax is an accumulation of blood between the lung and the chest wall.

Hemothorax can result from any injury—blunt or penetrating―that cuts or tears a lung or an artery or vein in the chest. Blood may then accumulate in the pleural space―between the two layers of tissue that cover the lungs. A large amount of blood may press on the lungs and make breathing difficult. When air as well as blood enters this space, the disorder is called hemopneumothorax. Occasionally, hemothorax is caused by chest surgery or another disorder, such as tuberculosis Tuberculosis (TB) Tuberculosis is a chronic contagious infection caused by the airborne bacteria Mycobacterium tuberculosis. It usually affects the lungs, but almost any organ can be involved. Tuberculosis... read more Tuberculosis (TB) or lung cancer Lung Cancer Lung cancer is the leading cause of cancer death in both men and women. About 85% of cases are related to cigarette smoking. One common symptom is a persistent cough or a change in the character... read more Lung Cancer .

Did You Know...

  • Most bleeding from a chest wound occurs inside the chest cavity, and very little blood is visible externally.

Symptoms of Hemothorax

Hemothorax is not painful, but the injury that caused it usually is. The severity of other symptoms depends in part on the amount of blood in the chest cavity. If the amount of blood is small, people usually have no other symptoms. People with a large amount of blood may feel short of breath, and breathing may be shallow and rapid. A massive amount of blood may cause blood pressure to become dangerously low (shock Shock Shock is a life-threatening condition in which blood flow to the organs is low, decreasing delivery of oxygen and thus causing organ damage and sometimes death. Blood pressure is usually low... read more ). The skin may be cool, sweaty, and bluish.

Diagnosis of Hemothorax

  • Chest x-ray

  • Sometimes ultrasonography

If doctors suspect hemothorax, they take a chest x-ray X-Rays of the Chest X-rays are a type of medical imaging that use very low-dose radiation waves to take pictures of bones and soft tissues. Chest x-rays are sometimes used in people who may have a heart disorder... read more X-Rays of the Chest or, particularly if rapid diagnosis is necessary, do a bedside ultrasound procedure called E-FAST (Extended Focused Assessment With Sonography in Trauma) to detect blood in the pleural space between the lung and the chest wall.

Treatment of Hemothorax

  • Intravenous fluid and sometimes blood products to maintain blood pressure

  • Chest tube insertion

Doctors give fluids intravenously to increase the amount of fluid in the bloodstream and thus increase blood pressure. If a large amount of blood has been lost, a blood transfusion Overview of Blood Transfusion A blood transfusion is the transfer of blood or a blood component from one healthy person (a donor) to a sick person (a recipient). Transfusions are given to increase the blood's ability to... read more Overview of Blood Transfusion is necessary.

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