Does delirium mean hallucinations?

There’s a certain wisdom to that vernacular understanding when people say you’re delirious meaning: there’s something very different about the way you’re acting now compared to the way you usually act. In the hyper-vigilant, agitated, worst form of delirium, patients often develop elaborate and very frightening delusions. A common one will be that they think they’re in prison, actually, and they’ll cry out for help. Another key feature of delirium is it waxes and wanes so patients will be very agitated and then an hour or two later will be fine.