Recommended categories for aetiology of illnesses
| Aetiology | ICD-11 | OSIICS | SMDCS | Notes |
| Allergic | (22) | MxA | 71 | |
| Environmental—exercise-related | (23) | MxE | 72 | Heat illness, hypothermia, hyponatraemia, dehydration. |
| Environmental—non-exercise | (22/7) | MxS | 73 | Includes sleep/wake, sunburn. |
| Immunological/ Inflammatory | (04) | MxY | 74 | |
| Infection | 01 | MxI | 75 | Viral, bacterial, parasitic. |
| Neoplasm | 02 | MxB | 76 | |
| Metabolic/nutritional | 05 | MxN | 77 | |
| Thrombotic/Haemorrhagic | (11/03) | MxV | 78 | |
| Degenerative or chronic condition | – | MxC | 79 | Chronic-acquired conditions. |
| Developmental anomaly | 20 | MxJ | 80 | Includes congenital conditions. |
| Drug-related/Poisoning | 22 | MxD | 81 | Includes pharma, illicit. |
| Multiple | MxX | 82 | ||
| Unknown or not specified | MxZ | 83 |
ICD, International Classification of Disease; OSIICS, Orchard Sports Injury and Illness Classification System; SMDCS, Sport Medicine Diagnostic Coding System.