The effects of going without sleep can start to show in as little as 24 hours, and the longest recorded time someone has gone without sleep is approximately 264 hours, or 11 consecutive days
. Though it is unclear exactly how long a human can survive without sleep, going 3 days without it can be very dangerous
. Here's what to expect regarding the effects of sleep deprivation:
- 24 hours After 24 hours of no sleep, you may experience drowsiness, irritability, impaired decision-making, and altered perception. Staying awake for 24 hours is comparable to having a blood alcohol concentration of 0.10 percent, which is over the legal limit for driving in most states
- 36 hours After 36 hours, you may experience extreme fatigue, hormone imbalances, decreased motivation, and inflexible reasoning. Also, staying awake for this period of time can alter bodily functions, including appetite, metabolism, temperature, mood, and stress level
- 48 hours After 48 hours, most people have difficulty staying awake and may experience microsleeps, which are brief periods of light sleep that can last up to 30 seconds. During these microsleeps, the brain is in a sleeplike state, and you might feel confused or disoriented afterward
- 72 hours After 72 hours, the urge to sleep will be overwhelming, and many people will be unable to stay awake on their own. Someone who goes three days without sleep will have a limited ability to think, especially regarding executive functions like multitasking and paying attention
- 120 hours As people near 120 hours without sleep, they may experience a rapid and severe decline in mental health, which can involve symptoms of psychosis
It's important to note that sleep requirements vary between people, and adverse health effects can occur once a person stays awake longer than 17 hours
. If you are experiencing sleep deprivation, it is best to talk to your doctor, who can help get to the root of your symptoms and help you get your sleep schedule back on track
