: a mental disturbance characterized by confusion, disordered speech, and hallucinations
Condition of disorientation, confused thinking, and rapid alternation between mental states. The patient is restless, cannot concentrate, and undergoes emotional changes (e.g., anxiety, apathy, euphoria), sometimes with hallucinations. Delirium usually results from a disorder affecting the brain such as central nervous system infection, head trauma, or mental disorder. In severe cases of withdrawal from alcohol, delirium tremens results not from the excessive alcohol consumption alone but from exhaustion, malnutrition (particularly lack of thiamine), and dehydration.