Numerous studies have found that insufficient sleep increases a person's risk of developing serious medical conditions, including obesity, diabetes, and cardiovascular disease.
Lack of adequate sleep over time has been associated with a shortened lifespan.
It can be quite tedious to explain and I'm headed out, but if you type that question in le google machine, you'll get lots of good articles on the subject. If you are in university, you can use the online database, search for peer-reviewed articles and/or journals, and read even more from actual studies (If you are not into medical jargon, the first would be the best option. /emoticons/[email protected] 2x" width="20" height="20" /> )
Sleep is really important for your physical and mental health. That's why when you are ill you feel tired - your body needs the rest to mend and repair. Everyone needs different amounts of sleep - it is just a question of working out what is right for you.
Our cells renew when we sleep. Systemic bodily functions differ in sleep than in a waking state. Without enough sleep we first go through mental malfunction, to hallucinations to actual death as discovered through forced sleep deprivation in clinical trials. Death will occur if forced deprivation continuously for most at about 5-6 days. The longest record is 11 days ending with myocardial infarction (heart attack)
Sleep plays a vital role in good health. Getting enough+quality sleep at the right times can help to protect your mental health, physical health, quality of life, and safety.
Everyone here has contributed a lot in this question. I just want to add that sleep gives you the chance to replenish. It is good not just because it gives you energy but it also allows your skin to breathe again. You will notice the difference in just a few days.