Under normal circumstances, one can't stay awake for a long time. Scientists have done an experiment: let some healthy people stay awake for 72 hours in a row, and as a result, they all have "mental abnormalities" one after another; Once the experiment is stopped and they are allowed to sleep for a few hours, these people will return to normal.

How much time should a person sleep every day? For most adults, sleeping for 8 hours every night is enough. The American Cancer Society made a survey, and the average person who sleeps 8 hours a day has the longest life expectancy. In contrast, the mortality rate of adults who sleep less than 4 hours a night is higher than180%; Adults who sleep more than 10 hours a night have a higher mortality rate of 80%.

However, people of different ages need different sleep times. Generally speaking, people aged 1-3 need to sleep 14- 16 hours a day, people aged 4-6 need to sleep 12- 14 hours, and people aged 7-9 need to sleep1/kloc.

Of course, the length of sleep also has a lot to do with long-term habits. Edison can regain his energy by sleeping for three hours every day, Napoleon can sometimes get rid of fatigue by taking a nap against a tree, but Einstein sleeps 10 hours every day.

Therefore, whether you get enough sleep varies from person to person. As long as you feel clear-headed and happy after waking up, you won't feel lack of sleep.