You may have heard people say "I'll sleep when I die." Truth is, their lack of sleep may actually precipitate death. Research shows that if you sleep less than six hours a night, you are at far greater risk of having a heart attack or experiencing a stroke [source: Roizen and Oz]. What's more, your mind seems to deteriorate at a faster pace.
On an emotional level, a lack of sleep makes you less peaceful and more prone to anger. Sicknesses related to viral infections are also more prevalent among people lacking proper rest. Eight hours of sleep each night is important for your current physical health, as well as your mood and your longevity [source: Roizen and Oz].