As well as leading to health problems like cardiovascular disease, it can also cause weight gain and it can severally effect the hormone production. This includes the growth hormone and testosterone in men. When you don't get enough sleep ( like over a 7 day time span) it will cause serious ramifications on your vision. Scientist believe it's possible that given enough time, sleep deprivation can kill you. Your mood changes very quickly when you are overly tired and you can become very irresponsible