This list is not exhaustive:
| Physiological | Transient choking/gagging, apnoea of prematurity |
| Cardiac | Congenital heart disease, arrhythmias, prolonged QT |
| Gastrointestinal | Gastro-oesophageal reflux |
| Respiratory | Airway obstruction including inhaled FB, laryngomalacia, obstructive sleep apnoea, central sleep apnoea |
| Infection | Whooping cough, URTI/LRTI, meningitis/encephalitis, UTI, gastroenteritis |
| CNS | Head injury, epilepsy, structural cerebral abnormalities, neuromuscular disorders |
| NAI | Inflicted injury e.g. drug ingestion, factitious illness, suffocation |
| Surgical | Acute gastrointestinal obstruction |
| Metabolic/toxins | Hypoglycaemia, hypocalcaemia, hypokalaemia, inborn errors of metabolism, intentional/non-intentional drug overdose |