Coughing Up Blood (Hemoptysis)
Coughing up blood (hemoptysis) can be a sign of a serious medical condition. Infections, cancer, and problems in blood vessels or in the lungs themselves can be responsible. Coughing up blood generally requires medical evaluation unless the hemoptysis is due to bronchitis.
Causes of Hemoptysis
There are many potential reasons for coughing up blood. Causes for coughing blood include:
- Bronchitis (acute or chronic), the most common cause of coughing up blood. Hemoptysis due to bronchitis is rarely life-threatening.
- Lung cancer or non-malignant lung tumors
- Use of blood thinners (anticoagulation)
- Pulmonary embolism
- Congestive heart failure, especially due to mitral stenosis
- Inflammatory or autoimmune conditions (lupus, Wegener’s granulomatosis, microscopic polyangiitis, Churg-Strauss syndrome, and many others)
- Pulmonary arteriovenous malformations (AVMs)
- Crack cocaine
- Trauma, such as a gunshot wound or motor vehicle accident
- Dieulafoy’s disease
Hemoptysis can also come from bleeding outside the lungs and airways. Severe nosebleeds or vomiting of blood from the stomach can result in blood draining into the windpipe (trachea). The blood is then coughed up, appearing as hemoptysis.
In many people with hemoptysis, no cause is ever identified. Most people with unexplained hemoptysis are no longer coughing up blood six months later.
In people who are coughing up blood, testing focuses on determining the rate of bleeding and any risk to breathing. The cause for hemoptysis must then be identified. Tests for coughing up blood include:
History and physical examination. By talking to and examining someone who is coughing up blood, a doctor gathers clues that help identify the cause.
Chest X-ray. This test may show a mass in the chest, areas of fluid or congestion in the lungs, or be completely normal.
Computed tomography (CT scan). By producing detailed images of structures in the chest, a CT scan can reveal some causes for coughing up blood.
Bronchoscopy. A doctor advances an endoscope (flexible tube with a camera on its end) through the nose or mouth into the windpipe and airways. Using bronchoscopy, a doctor may be able to identify the cause of hemoptysis.
Complete blood count (CBC). A test of the number of white and red blood cells in the blood, along with platelets (cells that help blood clot).
Urinalysis. Certain causes of hemoptysis also result in abnormalities on this simple urine test.
Blood chemistry profile. This test measures electrolytes and kidney function, which may be abnormal in some causes of hemoptysis.
Coagulation tests. Alterations in blood’s ability to clot can contribute to bleeding and coughing up blood.
Arterial blood gas. A test of the levels of oxygen and carbon dioxide in the blood. Oxygen levels can be low in people coughing up blood.
Pulse oximetry. A probe (usually on a finger) tests the level of oxygen in the blood.