| Age – 18 years or older. |
Systemic symptoms – weight loss, night sweats, fatigue/malaise. |
| Cough – unexplained and greater than 4 weeks duration. |
Respiratory disease – active tuberculosis, bronchiectasis, COPD, asthma. |
| Spirometry – normal. |
Cancer – history of cancer (non-melanoma skin cancer acceptable). |
| Chest x-ray – normal or minor abnormalities unlikely to explain cough, e.g., calcified granuloma. |
Cardiac disease – myocardial infarction within past 12 months, heart failure within last 12 months. |
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Blood disorders – examples: anemia, platelet disorders, coagulation disorders, neutropenia, lymphocytopenia. |
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Other systemic diseases, examples: collagen disorders (temporal arteritis, Ehlers–Danlos syndrome, systemic lupus erythematous), Chron’s disease or dysphagia. |
