| Haemoptysis |
| Severe chest pain |
| Dyspnoea |
| High fever |
| TB |
| Stay in countries with high prevalence of TB |
| Contact with a person stricken with TB |
| Homelessness |
| Illicit drug users |
| Immunosuppressed states |
| Immune deficiency e.g. CVID |
| HIV infection |
| Immunosuppressive therapy |
| History of malignant tumour |
| History of heavy smoking |
TB: tuberculosis, CVID: common variable immunodeficiency.