When You Pull An All-Nighter, This Is What Happens To Your Body

Almost everyone has been through an all-nighter. Maybe your child wouldn't sleep, or you had a deadline coming up. Or maybe you and your friends were having too much fun to let something like sleep bring the night to an end. Whatever the reason, we've gone from one morning to the next without a moment of rest in between.

Of course when you're up all night to have fun, there is a good chance you've got the next day off to sleep off the exhaustion. And, hopefully, tired parents can get some rest while friends or relatives keep an eye on their child. But what about deadlines? What does an all-nighter do to your body when you stay up to finish a task that can't be put off any longer?

The short answer is: nothing good. All-nighters may seem like a good idea on the surface, but they end up costing us more in the long run. Students — usually big fans of all-nighters — should be especially wary. A 2007 study from St. Lawrence University found that all-nighters were actually linked to lower grades, not higher.

Of course, grades aren't the only thing to suffer. Our bodies, our appetites, and our self-control are all affected when we skip a night of sleep. A 2004 study funded by the National Institutes of Health found that sleep deprivation increases ghrelin — a hormone that controls hunger — while decreasing the satiety hormone leptin.

After an all-nighter, you may as well be drunk

The National Institute for Occupational Safety and Health (NIOSH), run by the CDC, is no stranger to the effects of sleep deprivation on the human body. And pulling an all-nighter is a form of sleep deprivation. In fact, sleep scientists actually refer to it as "total sleep deprivation" because our bodies get no rest when we put them through all-nighters (via Progress in Brain Research).

Sleep deprivation carries some serious risks, all of which NIOSH lays out in a module designed to warn nurses about these risks, as well as strategies to avoid the worst of them. These risks include increased chances of infection from viruses like the flu because sleep deprivation suppresses the immune system. Sleep deprivation also damages cardiovascular health by increasing levels of cortisol (known as "the stress hormone") and spiking activity in the sympathetic nervous system.

NIOSH even covers the physical impact of sleep deprivation, starting with a list of tragedies caused by sleep deprivation that includes the Challenger accident and the Exxon Valdez oil spill. Sleep deprivation reduces our ability to focus, aim, react to sudden changes, and judge distances. It's a lot like being drunk. In fact, 17 hours without sleep is similar to having a blood alcohol content of (BAC) .05% and after 24 hours, it's more like having a BAC of .10%

All-nighters just aren't worth it. Your memory suffers, your body suffers, and your health suffers. The better bet is to put the task aside, get some sleep, and wake up earlier the next morning to finish what you couldn't the night before. Your body will thank you.