Hemothorax Causes, Treatment, and Prognosis

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A hemothorax is defined as the accumulation of blood between the membranes lining the lungs (the pleura). The most common cause is trauma, but heart and lung surgery, cancer, lung infections, or even excess doses of blood thinners may also be responsible. Symptoms may include the onset of severe shortness of breath, chest pain, and symptoms of shock. A chest tube is usually inserted to drain the blood, but chest surgery is often necessary to define and address the underlying cause. Prompt treatment is important to reduce the risk of developing fibrosis of the lung lining or an empyema (pus in the pleural cavity).

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It's thought that close to 300,000 cases of hemothorax occur in the United States each year due to trauma alone, with chest injuries present in roughly 60 percent of patients with multiple trauma injuries. When a hemothorax develops, however, there is often confusion at first because there are so many similarities in the symptoms of a hemothorax and other respiratory complications. What should you know if you are facing this condition in yourself or a loved one?


Symptoms of a hemothorax can be difficult to distinguish from those of other conditions at first and may include:

  • Severe shortness of breath
  • Anxiety and extreme restlessness
  • Symptoms of shock such as a rapid heart rate, low blood pressure, pale, cold extremities, and weakness
  • Chest pain which is often sharp and may vary with position. Pain with deep breathing may also occur
  • A feeling of impending doom


There are many possible causes of a hemothorax, and depending on the cause, the blood may originate from the lungs, the heart, the chest wall, or the large blood vessels present in the chest. Some of these include:

  • Trauma to the chest (this is the most common cause of a hemothorax).
  • Emphysema
  • Lung cancer,
  • Pleural mesothelioma, (a cancer that involves the pleura)
  • Cancers that are metastatic (spread) to the lung such as breast cancer and colon cancer
  • Chest surgery (most commonly following lung and heart surgery)
  • Biopsy of lung masses
  • Lung infections such as tuberculosis
  • Bleeding disorders that result in prolonged clotting, or excess doses of blood thinners
  • Pulmonary embolism and infarcts
  • Spontaneous


A careful history may give some clues to the cause and presence of a hemothorax—such as a chest trauma or chest surgery. On the side affected, lung sounds may be diminished or absent. An upright chest X-ray may help to diagnose a hemothorax, and further testing, such as a chest CT may then be considered. When a chest tube is placed, the fluid may be evaluated to confirm the presence of blood in the pleural cavity and further look for possible causes.

Evaluation of the pleural fluid can be helpful as well. For this fluid to be classified as a hemothorax, the hematocrit of the pleural fluid should be at least 50 percent of the hematocrit of the peripheral blood (blood examined by taking a sample from a vein).

Differential Diagnosis

A hemothorax is different than some other conditions involving the thorax such as:


Initial treatment for a hemothorax usually involves stabilizing the person and then inserting a chest tube to drain the blood and air that has built up or is building up between the lung membranes in the pleural cavity.

Often, a hemothorax is a result of blunt or penetrating trauma to the chest. When it occurs without trauma, it's very important to find and treat the underlying cause.

Treatment usually involves inserting a chest tube as part of a video-assisted thoracostomy (a minimally invasive surgery in which small incisions are made in the chest and a surgery is done through these small incisions with the use of a camera).

For some people surgery, a thoracotomy (open chest surgery in contrast to minimally invasive surgery) is needed to get to the source and control the bleeding, especially in the setting of large hemothorax or when the source of the bleeding is uncertain.


For those people who receive treatment, a small number are left with an empyema (a collection of pus between the membranes lining the lungs) or some scarring of the pleura (pleural fibrosis). Fibrosis may result in long-term respiratory symptoms for some people.

With an empyema, further surgeries may be done to remove the pus and to prevent further fluid and bacteria from entering the chest. Treatments for fibrosis are primarily supportive as fibrosis is usually irreversible. That said, treatments ranging from pulmonary rehabilitation to breath training can be helpful in restoring the best quality of life possible.


The outcome of a hemothorax is determined by both the extent of the bleeding, and the underlying cause. For people who sustain a hemothorax as a result of chest trauma, the overall prognosis is actually quite good, and excellent if the hemothorax can be adequately treated. Prognosis may also be good when the hemothorax occurs as a complication of a biopsy or chest surgery. When a hemothorax occurs in the presence of cancer (due to growth of the tumor through the lung lining) or a pulmonary infarct, however, the prognosis is more guarded.

A Word From Verywell

If you or a loved one have experienced a hemothorax is can be terrifying. Fortunately, if the bleeding can be controlled and excellent medical care is available, treatment can sometimes resolve the problem with minimal long term effects.

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6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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