What are the differential diagnoses for an adult patient presenting with hemoptysis?

Differential Diagnoses for Adult Hemoptysis

Bronchiectasis is the leading cause of hemoptysis in most tertiary referral centers, followed by chronic bronchitis, lung cancer, and respiratory tract infections. 1

Most Common Etiologies

Bronchiectasis (Leading Cause)

• Accounts for 26-34% of hemoptysis cases and represents the most frequent diagnosis in tertiary care settings 1, 2
• Particularly prevalent in patients with chronic inflammatory conditions, cystic fibrosis, or prior tuberculosis 1
• Significantly more common in nonsmokers, especially those with moderate-to-severe bleeding or tuberculosis history 2
• Presents with recurrent respiratory infections causing intermittent fever 3

Chronic Bronchitis and Acute Respiratory Infections

• Chronic bronchitis accounts for approximately 23% of cases 2
• Acute bronchitis represents up to 63% of mild hemoptysis cases 4, 1
• Acute respiratory tract infections are among the most common causes in young adults 5

Malignancy

• Lung cancer is the second most common cause in patients with hemoptysis and normal chest radiographs 1
• Accounts for 13% of cases overall, but presents with hemoptysis in >65% of patients with bronchogenic carcinoma 1, 2
• Centrally-located tumors particularly stimulate cough receptors causing bleeding 1
• Only found in smokers in prospective studies; smokers with normal chest X-rays have 5.4-fold increased risk if X-ray is abnormal 2
• Metastatic disease to lungs can also cause hemoptysis, though less commonly than primary lung cancer 1

Tuberculosis and Mycobacterial Disease

• Active tuberculosis remains a major cause globally, particularly in endemic areas and young adults 1, 3
• Commonly presents with intermittent fever 3
• Nontuberculous mycobacterium accounts for 24% of cases in some series 1
• Pulmonary aspergillomas frequently develop in pre-existing TB cavities, causing recurrent hemoptysis with 55% recurrence rates 1

Infectious Causes

• Bacterial pneumonia, particularly common in immunocompromised patients including those with chronic kidney disease on hemodialysis 1
• Fungal infections, especially aspergillomas in pre-existing cavities, cause both acute and recurrent bleeding 1
• Lower respiratory tract infections are common in children 6

Vascular Causes

• Pulmonary arteriovenous malformations require embolization 1, 5
• Pulmonary artery aneurysms and pseudoaneurysms, particularly in chronic inflammatory disease 1
• Mitral stenosis causes hemoptysis through chronic pulmonary venous hypertension, presenting with elevated left main bronchus and parahilar interstitial infiltrates on imaging 1
• Pulmonary embolism is an uncommon cause but should be considered with prolonged immobility 5

Trauma-Related Etiologies

• Pulmonary contusion from falls or physical trauma, especially in intoxicated patients with altered consciousness 5
• Rib fractures with pulmonary parenchymal injury 5
• Aspiration pneumonitis/pneumonia is a leading consideration in patients with high alcohol levels, impairing protective airway reflexes 5
• Chemical pneumonitis from gastric acid aspiration can cause diffuse alveolar hemorrhage 5

Systemic and Immune-Mediated Causes

• Immune-complex mediated diseases such as HCV-associated glomerulonephritis causing pulmonary-renal syndromes 1
• Autoimmune disease causing pulmonary capillaritis can present with diffuse alveolar hemorrhage in young adults 3, 5
• Sarcoidosis with advanced pulmonary disease causes hemoptysis requiring palliative treatment 1

Coagulopathy

• Alcohol-induced coagulopathy from chronic liver disease or acute platelet dysfunction, though less common in young patients without chronic alcohol use 5

Cryptogenic Hemoptysis

• No identifiable cause is found in 20-34% of cases despite complete evaluation 1, 7, 6
• These patients often respond well to bronchial artery embolization with 97% remaining free of hemoptysis at 20 months 1

Geographic and Population-Specific Considerations

• In developed countries, malignancy prevalence exceeds tuberculosis as a cause 4
• In resource-limited areas, tuberculosis remains the leading cause 8
• In chronic kidney disease patients on hemodialysis, respiratory tract infections are more common due to immunocompromised state 1
• In postpartum women, mitral stenosis should be considered as pregnancy increases cardiac output and can precipitate pulmonary hypertension 1

Critical Pitfalls to Avoid

• Even small amounts of blood-streaked sputum should raise concern for endobronchial tumor in patients with risk factors such as smoking or occupational carcinogen exposure 1
• Foreign body aspiration is a common cause in children and should not be overlooked 6
• Nonsmokers with moderate/severe hemoptysis and/or previous tuberculosis infection warrant high-resolution CT evaluation for bronchiectasis 2
• Smokers with hemoptysis require extensive evaluation with chest CT and bronchoscopy due to increased lung cancer risk 2