Delirium

A state of acute mental confusion, commonly brought on by physical illness. Symptoms vary according to personality, environment, and the severity of illness. They may include failure to understand events or remember what has been happening, physical restlessness, mood swings, hallucinations, and terrified panic. High fever and disturbances of body chemistry are commonly present. Children and older people are most susceptible to delirium, particularly during infection, after surgery, or when there is a pre-existing brain disturbance such as dementia. Drugs, poisons, and alcohol are common precipitants.