An essential part of diagnosing hemoptysis is ruling out hematemesis (vomiting of blood) and other forms of pseudohemoptysis (blood in the sputum that originates outside of the respiratory tract). Blood can originate in the back of the mouth (an area known as the oropharynx) or in the gastrointestinal tract.
After confirmation of hemoptysis, diagnosis involves differentiating among the possible causes of the bleeding, from lung cancer to bronchitis. The diagnosis involves a detailed medical history, laboratory tests, and a chest x-ray.
It may also involve a bronchoscopy or CT scan, depending on the nature of the hemoptysis and likelihood of cancer. If the underlying cause may be related to a vascular disorder (a blood vessel disorder), a pulmonary angiography may be done.
The first part of the diagnosis is a thorough medical history. A history of the symptoms can provide important clues about the source of the blood and whether the patient is experiencing hemoptysis or pseudohemoptysis.
The doctor will ask about any abnormalities, from vomiting to the color of stools. They will also ask the patient about the color and consistency of the blood.
The physician will ask questions to find clues about what is causing the hemoptysis and how serious the condition is. The first questions involve the patient's history of smoking and other cancer-related risk factors.
Because bronchitis, bronchiectasis, and TB are some of the most common causes of hemoptysis, these are usually the first causes that a physician suspects and must confirm or eliminate in the diagnosis. If the hemoptysis is mild, it is an indication of chronic bronchitis and if it is massive, it is an indication of bronchiectasis or TB.
What does the blood look like?
Although the blood that comes from the respiratory tract is usually bright red and frothy, its appearance and consistency can vary considerably. Sometimes this variation can provide important clues about the underlying disorder.
For example, if the patient is coughing up purulent sputum (thick, opaque, yellowish-white discharge) mixed with blood, the physician will likely suspect an underlying pulmonary infection. If the patient is spitting up blood without pus, the doctor will probably examine the likelihood of TB, cancer, or pulmonary infarction. If the blood is foul-smelling, it may indicate a lung abscess or infection. If the patient is coughing up pink, frothy sputum, they may have pulmonary edema.
Pattern of bleeding
The pattern of bleeding can provide helpful clues about what is causing the hemoptysis. For example, patients with bronchitis or bronchiectasis usually have recurrent, brief episodes. If the bleeding occurs monthly, it may be menstrual-related, known as catamenial hemoptysis.
It is helpful for the physician to know about other symptoms that accompany the hemoptysis. Unexplained weight loss prior to the hemoptysis episodes may be an indication of cancer. A history of night sweats, fever, and general ill health suggests TB.
Risk factors for causative conditions
Because of the seriousness of lung cancer, patients with hemoptysis should be evaluated for the likelihood of bronchogenic carcinoma. Risk factors include the following:
- Over 40 years of age
- History of smoking
- Hemoptysis that has lasted longer than a week
- Coughing up large amounts of blood (more than about 30 mL per episode)
If a patient is at risk for lung cancer, more invasive diagnostic tests, such as a bronchoscopy with biopsy, are indicated.
It is also helpful to evaluate risk factors for illnesses other than cancer. If, for example, the patient has traveled recently where there is an infectious agent (parasite, virus, fungus, bacteria) known to cause hemoptysis, this is helpful information to the physician. It is also important to know if the patient has experienced any trauma to the chest.