Correct answer:

(1) Central nervous system: trauma and disease (e.g. cerebrovascular accident (commonest), epilepsy, subarachnoid haemorrhage, cerebral tumour, abscess and meningitis) (2) Drugs: alcohol, carbon monoxide, barbiturates, aspirin and opiates. (3) Diabetes: hyperglycaemia and hypoglycaemia. (4) Uraemia. (5) Hepatic failure. (6) Hypertensive encephalopathy. (7) Profound toxaemia. (8) Hysteria. It is usually easy enough to determine that unconsciousness is due to trauma, but it is important to remember that a drunk or epileptic person, for example, may have struck his or her head in falling so that the condition is complicated by a head injury.