Every person needs sleep everyday. But with the high development of society, most people have more and more things to do and have less time to sleep. As a result, many people are lack of sleep. For a short time, they may not realize the bad side of it, but it will bring something bad for them after a long term. First of all, lack of sleep will do harm to people’s look. If they do not sleep enough, they will get black eyes and bad skin easily, which will make people look no so beautiful. Secondly, lack of sleep is bad for the spiritual outlook. A person who lacking of sleep always looks tired and has no power to do things. Last, not enough sleep for a long time will have bad influence of thought. They always can’t be active in mind.人人每天都需要睡觉。但是随着社会的快速发展，大多数人都是事情越来越多，而睡觉的时间却是越来越少。所以很多人都是睡眠不足。短期的睡眠不足并不会感觉到有什么特别的不适，但是长期以往就会感受到了。首先，睡眠不足会影响到外貌。如果说不够，很容易会有黑眼圈，皮肤也容易不好，这样看起来就没有那么漂亮了。其次，缺少睡眠也影响到一个人的精神面貌。经常睡眠不足的人看起来会比较疲惫，感觉做什么都无力。最后，长期缺少睡眠还会影响思维，经常做不到思维活跃。