While the absolute maximum,, is not clearly defined, humans have stayed awake for over 11 days (roughly 264 hours) in recorded, supervised scenarios. However, severe cognitive impairment, hallucinations, and paranoia typically begin within 3 to 4 days. Key Effects of Sleep Deprivation: 24 Hours: Cognitive impairment similar to a \(0.10\%\) blood alcohol content, including poor decision-making, irritability, and reduced focus.36-48 Hours: Extreme fatigue, hormonal changes, and the onset of hallucinations.72+ Hours: Severe confusion, paranoia, and potential psychosis. Important Considerations: Safety Limits: Guinness World Records stopped tracking this category due to dangerous health risks.Long-Term Health: Chronic lack of sleep is linked to heart disease, diabetes, and mental health issues.Fatal Familial Insomnia: This is a rare, fatal genetic disease that causes severe, permanent insomnia, but is distinct from voluntary sleep deprivation. For most, the urge to sleep becomes uncontrollable long before reaching the 11-day mark, and attempting to go without sleep is extremely hazardous to physical and mental health.