What are the possible causes of hemoptysis in individuals with varying demographics and past medical histories, such as chronic obstructive pulmonary disease (COPD), lung cancer, or a history of smoking or travel to endemic areas?

Causes of Hemoptysis

The most common causes of hemoptysis vary by geographic location and clinical setting: in outpatient primary care, acute respiratory tract infections, COPD, malignancy, and bronchiectasis predominate; in tertiary referral centers in North America and Europe, bronchiectasis, respiratory infections, and lung carcinomas are most common; while tuberculosis and its sequelae remain the leading cause in developing countries. 1

Geographic and Setting-Specific Etiologies

Developed Countries (North America/Europe)

In large tertiary referral centers, bronchiectasis is the leading cause of hemoptysis, followed by chronic bronchitis, lung cancer, and respiratory tract infections. 2

• Bronchiectasis accounts for the majority of cases in large studies, particularly in patients with chronic inflammatory conditions, cystic fibrosis, or prior tuberculosis 2
• Lung cancer is the second most common cause in patients with hemoptysis and normal chest radiographs, presenting with hemoptysis in >65% of cases, particularly with centrally-located tumors 2
• Chronic bronchitis and acute respiratory infections are common causes, with acute bronchitis representing up to 63% of mild hemoptysis cases 2
• Nontuberculous mycobacterium accounts for 24% of cases in some series 2

Developing Countries

Tuberculosis and its sequelae remain the most prevalent cause of hemoptysis in developing countries. 1

• In endemic regions (Asia, Africa, Middle East), tuberculosis represents the dominant cause of massive hemoptysis, accounting for 55-74% of cases requiring bronchial artery embolization 3
• Chinese studies show 55-100% of hemoptysis cases related to active or sequelae TB 3
• Indian series report 74% of hemoptysis cases due to TB 3
• Egyptian data demonstrate 57% of massive hemoptysis from active or post-TB disease 3

Specific Etiologies by Category

Infectious Causes

• Bacterial pneumonia is particularly common in immunocompromised patients, including those with chronic kidney disease on hemodialysis 2
• Active tuberculosis remains a major cause globally and should be considered in endemic areas or high-risk populations (elderly nursing home residents, prisoners) 2, 3
• Fungal infections, particularly aspergillomas in pre-existing cavities, cause both acute and recurrent bleeding with high recurrence rates of 55% 2

Malignant Causes

• Bronchogenic carcinoma presents with hemoptysis in >65% of cases, particularly with centrally-located tumors that stimulate cough receptors 2
• Even small amounts of blood-streaked sputum should raise concern for endobronchial tumor in patients with risk factors such as smoking or occupational exposures 2
• Metastatic disease to the lungs can cause hemoptysis, though less commonly than primary lung cancer 2

Vascular Causes

• Pulmonary arteriovenous malformations can cause significant bleeding and require embolization 2
• Pulmonary artery aneurysms and pseudoaneurysms are potential sources, particularly in patients with chronic inflammatory disease 2
• Mitral stenosis causes hemoptysis through chronic pulmonary venous hypertension, presenting with classic radiographic findings of elevated left main bronchus and parahilar interstitial infiltrates 2

Systemic and Immune-Mediated Causes

• Sarcoidosis with advanced pulmonary disease causes hemoptysis that typically requires palliative treatment, as these patients are often not surgical candidates 1
• Autoimmune diseases resulting in capillaritis or cavitation, including immune-complex mediated diseases such as HCV-associated glomerulonephritis, can cause pulmonary-renal syndromes with hemoptysis 1, 2
• Coagulopathies are additional causes to consider 1

Other Causes

• Sequelae from respiratory infections including post-TB bronchiectasis and destroyed lung continue to cause bleeding decades after microbiologic cure 3
• Pulmonary embolus is an uncommon cause of hemoptysis, with only a single study reporting it as one of the primary causes 1

Cryptogenic Hemoptysis

No identifiable cause is found in approximately 20% of patients initially presenting with hemoptysis despite extensive investigation by both CT and bronchoscopy. 1

• Cryptogenic hemoptysis has been reported as high as 50%, though this upper range is likely inflated because of incomplete investigation with either CT or bronchoscopy 1
• These patients often respond well to bronchial artery embolization with 97% remaining free of hemoptysis at 20 months 2

Critical Clinical Pitfalls

Always consider tuberculosis in high-risk populations (endemic areas, elderly nursing home residents, prisoners), as these populations have atypical presentations with less fever and hemoptysis but similar cough prevalence. 3

Recognize that post-TB sequelae cause hemoptysis decades after cure, with destroyed lung, bronchiectasis, and aspergillomas continuing bleeding long after microbiologic cure. 3

In patients older than 50 years with a positive smoking history, extensive evaluation and follow-up is needed to exclude lung carcinoma, even with minimal hemoptysis. 4