Evidence shows that we as humans need between seven to nine hours of sleep each night in order for our memory to function — so if we don’t sleep, we don’t learn. Although many of us tend to understate the importance of sleep, we may not realize lack of sleep can lead to various major health concerns, including depression, high blood pressure, high risk of diabetes, cardiovascular disease, obesity, and premature death. So what can actually happen if we avoid sleep altogether?

A 24-year-old man in the 1930s decided that he did not need to sleep anymore because “sleep is a habit” and he was determined to break the habit. The man asked a group of researchers to document his hiatus from sleep who, in turn, gave him a typewriter and asked him to write for 30 minutes a day to act as a measurement of how a lack of sleep was affecting his cognitive abilities. While the man’s blood pressure, pulse, and chemicals in his pee all stayed the same after 10 days without sleep, his typing speed declined with each passing day of sleeplessness, and by day four he was completely unable to type because he could not make out letters and numbers.

According to the National Sleep Foundation, Americans between the ages of 13 and 64 say they rarely or never get an appropriate night’s sleep on weeknights. Around 15 percent of adults between the ages of 19 and 64 and seven percent of teenagers between 13 and 18-year-olds say they sleep less than six hours on weeknights. Avoiding sleep to complete a task or take care of other pressing issues tends to be counterproductive and often leads to mistakes. So sleep on it!