Harvard Mental Health Letter

Recognizing and managing delirium

Sudden confusion, especially in the elderly, may be a sign of delirium.

During illness, hospitalization, or recovery, some people experience delirium, a rapidly developing and severe confusion accompanied by altered consciousness and an inability to focus. It's one of the most common complications of hospitalization among older people, affecting as many as 20% of those ages 65 and over who are admitted to hospitals.

Anything that interrupts normal brain function can cause delirium. Inflammation or toxic substances can interfere with brain function, for example, by disturbing the neurotransmitters that nerve cells use to communicate. Though the causes of delirium are complex, one major pathway involves the neurotransmitter acetylcholine. If blood sugar levels fall too low or the brain doesn't receive enough oxygen, acetylcholine transmission plummets.

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