Every man, woman and child requires sleep. Its purpose is somewhat unknown, except that it seems to allow our body and mind to regenerate and recharge. Each person varies in the amount of sleep required and many chemicals, such as caffeine and nicotine, can affect the quality of sleep. The body cycles through different stages of sleep from light, transitional non-REM sleep to deep sleep to rapid eye movement (REM) sleep. There are many consequences of not getting the proper amount or quality of sleep during the night. These include dozing off at inappropriate times of the day, higher risk of car accidents, and lower pain threshold/tolerance.