Causes of Hemoptysis
Most Common Etiologies
Bronchiectasis is the leading cause of hemoptysis in most tertiary referral centers, followed by chronic bronchitis, lung cancer, and respiratory tract infections. 1
Primary Causes by Frequency
- Bronchiectasis accounts for the majority of cases in large studies, particularly in patients with chronic inflammatory conditions, cystic fibrosis, or prior tuberculosis 1, 2
- Chronic bronchitis and acute respiratory infections (including bacterial pneumonia) are common causes, with acute bronchitis representing up to 63% of mild hemoptysis cases 1, 3, 4
- Lung cancer (both primary and metastatic) is the second most common cause in patients with hemoptysis and normal chest radiographs, and should be strongly suspected in patients with occupational carcinogen exposure 1, 5, 3
- Tuberculosis and nontuberculous mycobacterium remain significant causes, with nontuberculous mycobacterium accounting for 24% of cases in some series 1, 3
- Pulmonary aspergillomas (chronic or simple) frequently develop in pre-existing cavities from tuberculosis and cause recurrent hemoptysis with high recurrence rates of 55% 1
Infectious Causes
- Bacterial pneumonia is particularly common in immunocompromised patients, including those with chronic kidney disease on hemodialysis 2, 6
- Active tuberculosis remains a major cause globally and should be considered in endemic areas or high-risk populations 1, 3
- Fungal infections, particularly aspergillomas in pre-existing cavities, cause both acute and recurrent bleeding 1
Malignant Causes
- Bronchogenic carcinoma (squamous cell and small cell) presents with hemoptysis in >65% of cases, particularly with centrally-located tumors that stimulate cough receptors 5, 6
- Metastatic disease to the lungs can cause hemoptysis, though less commonly than primary lung cancer 2, 3
- Even small amounts of blood-streaked sputum should raise concern for endobronchial tumor in patients with risk factors such as smoking or occupational exposures 5
Vascular Causes
- Pulmonary arteriovenous malformations can cause significant bleeding and require embolization 2, 7
- Pulmonary artery aneurysms and pseudoaneurysms are potential sources, particularly in patients with chronic inflammatory disease 2, 7
- Mitral stenosis causes hemoptysis through chronic pulmonary venous hypertension, presenting with classic radiographic findings of elevated left main bronchus and parahilar interstitial infiltrates 8
- Pulmonary embolism can cause hemoptysis, though less commonly than other causes 3, 7
Systemic and Immune-Mediated Causes
- Immune-complex mediated diseases such as HCV-associated glomerulonephritis can cause pulmonary-renal syndromes with hemoptysis 2
- Sarcoidosis with advanced pulmonary disease causes hemoptysis that typically requires palliative treatment, as these patients are often not surgical candidates 1
- Vasculitis affecting the pulmonary vasculature can present with hemoptysis 3, 7
Cryptogenic Hemoptysis
- No identifiable cause is found in 20-34% of cases despite complete evaluation, though these patients often respond well to bronchial artery embolization with 97% remaining free of hemoptysis at 20 months 1, 6, 4
Special Populations
Chronic Kidney Disease Patients on Hemodialysis
- Respiratory tract infections are more common due to immunocompromised state 2
- Vascular malformations and aneurysms occur with higher frequency 2
- Bleeding diathesis from uremia can exacerbate hemoptysis 2
Postpartum Women
- Mitral stenosis should be considered, as pregnancy increases cardiac output and can precipitate pulmonary hypertension with hemoptysis 8
Critical Pitfall to Avoid
Do not dismiss small amounts of blood-streaked sputum as benign bronchitis, especially in patients with occupational exposures, smoking history, or constitutional symptoms—lung cancer must be excluded. 5 Normal chest radiography reduces but does not eliminate the likelihood of malignancy, and CT chest with IV contrast should be performed in all patients with frank hemoptysis and risk factors 1, 5, 3