Sleeping four hours a day is considered sleep deprivation and has the potential to affect your health. The human body should get enough sleep to ensure that it is awake during the day and alert enough for daily life, and it needs to maintain good health, usually adults need 7-9 hours a day to ensure that they are awake enough for the next day. If you don’t get enough sleep for a long period of time, on the one hand, you are prone to accidents, such as fatigue driving, which can cause car accidents. On the other hand, it may have an impact on the workplace, where excessive fatigue may lead to mistakes. In addition, health issues are more important, if there is not enough sleep, may weaken the immune system’s ability to fight infection, may also increase the risk of obesity, heart disease. Without adequate sleep, you may feel tired all the time, be very stressed, and lose interest in various activities you once enjoyed. Therefore, to ensure adequate sleep, four hours of sleep a day is not enough.