Hemoptysis is a symptom that involves coughing up blood. This signifies pathology within the airways and lung tissue that collectively form the respiratory system. The differential diagnosis, or list of potential causes, for hemoptysis is extensive, including conditions that are benign as well as malignant. A physician who evaluates a case of hemoptysis must consider all of the possibilities.
Causes
Many causes of hemoptysis can be categorized by anatomic location within the respiratory tract. They are summarized as follows:
- Lung Airways: The airways of the respiratory tract, including the trachea, large bronchi, and small bronchioles, can bleed when benign or malignant tumors grow and break the airway epithelial lining. Additionally, acute or chronic bronchitis can cause bleeding, particularly for the bronchioles. Other causes of hemoptysis from within the lung airways include, but are not limited to, trauma, damaged bronchioles that become dilated (bronchiectasis), and bronchogenic cysts.
- Lung Parenchyma: Often, hemoptysis that originates from the non-airway lung tissue involves an infection. This can be pneumonia, an infection encased in fibrous tissue (abscess), tuberculosis, a ball of fungus (aspergilloma), or other pathogen. Other causes of bleeding from the lung parenchyma include, but are not limited to, trauma, tumors, and autoimmune conditions such as Goodpasture's syndrome.
Besides these pulmonary etiologies, hemoptysis can also be due to non-pulmonary causes that eventually involve the respiratory tract. For example, a variety of cardiovascular conditions can lead to blood leakage into the lungs, including mitral valve stenosis, aortic dissection, and left ventricular failure. A variety of bleeding disorders can also lead to hemoptysis.
Evaluation
When evaluating a patient with hemoptysis, a physician may ask for further details about the symptom. This is because bleeding from within the nasal and oral cavities may produce blood-tinged sputum that can mistakenly be assumed to come from the lungs. The evaluation may also involve a physical examination and a chest x-ray. In cases where the diagnosis still remains uncertain, computed tomography (CT) of the chest can provide further information.
Treatment
The first step in the treatment of hemoptysis is to stop any active bleeding and prevent asphyxiation from blood in the lungs. This can be done with methods such as cauterization and localized injection of epinephrine. Once that is accomplished, then other necessary measures are performed to address the underlying cause, such as surgery for tumors in the respiratory tract.
References
- Merck Manual - Hemoptysis
- Weinberger, Steven E. "Etiology and Evaluation of Hemoptysis in Adults." In: Rose, Burton D., editor. UpToDate. Waltham, MA: UpToDate, 2009.
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