Table 1 Co-morbidities that cause cognitive impairment and hallucinations
| Metabolic | Hypoxia, hypercalcaemia, hyponatraemia, renal failure, liver failure, dehydration |
| Drug-induced | Opioids, benzodiazepines, tricyclics, corticosteroids, chemotherapy, drug withdrawal |
| Recreational drugs | Including alcohol and alcohol withdrawal |
| Infection | Particularly Urinary Tract Infection in the elderly |
| CNS | Cerebral metastases, Leptomeningeal metastases, cerebrovascular incident, head injury |
| Terminal phase | Pre-terminal agitation is a recognised phenomenon |