A person may become delirious after how many days without water?

A person may start to experience delirium after approximately four days without water because the human body typically can only survive about three to five days without hydration, depending on various factors such as temperature, exertion, and individual health conditions. By the fourth day without water, significant dehydration can set in, leading to severe physiological and cognitive effects.

The onset of delirium is related to the body's struggle to maintain essential functions without adequate fluids, as dehydration can disrupt electrolyte balance and brain function. This phase of dehydration often involves confusion, disorientation, and an inability to think clearly, which characterizes delirium. In contrast, while two days without water may lead to initial signs of dehydration and discomfort, cognitive impairment such as delirium usually takes longer to develop. Hence, four days is generally recognized as the point when severe impairment may manifest.