Mode of onset and causes of illness (modified from references 2, 5, 19 and 20)
| Mode of onset | Causes of sudden illness | Causes of gradual onset illness |
|---|---|---|
| 1. Sudden onset incident 2. Gradual onset incident | 1.1. Pre-existing disease (exacerbations of allergy, asthma, diabetes, degenerative, systemic inflammatory disorders, congenital, etc) 1.2. Infectious (viral, bacterial, fungal, etc) 1.3. Environmental (heat, cold, altitude, etc) 1.4. Nutritional, endocrine or metabolic disturbance 1.5. Drug related or toxic reaction 1.6. Exercise related (dehydration, exhaustion, etc) 1.7. Psychiatric 1.8. Other/idiopathic | 2.1. Pre-existing disease (exacerbations of allergy, asthma, diabetes, degenerative, systemic inflammatory disorders, congenital, etc) 2.2. Infectious (viral, bacterial, fungal, etc) 2.3. Environmental (heat, cold, altitude, etc) 2.4. Nutritional, endocrine or metabolic disturbance 2.5. Drug related or toxic reaction 2.6. Exercise related (dehydration, exhaustion, etc) 2.7. Psychiatric 2.8. Other/idiopathic |