Etiology

Etiology
Direct causes:

• Primary lung cancer
• Metastasis
• Tumours affecting the upper/lower airway obstruction
• Mesothelioma

Indirect causes:

• Pleural effusion
• Anaemia
• Chemotherapy/radiation-induced lung damage
• Pulmonary embolism
• Surgery complications
• SVC obstruction

Non-malignant causes:

• Pneumonia
• COPD
• Anxiety
• Heart failure