Sleep is essential to maintain the healthy bodies that need to carry out various duties today. Majority of the people today are sacrificing sleep for productivity and output which is a commendable effort but only for a limited time. Bodies are not machines. Thus in that sense we all know that in the same way that most people get sick, the same will hold true if we abuse our bodies by not giving them proper rest.

For a better medical understanding read on this:

When it’s sleep-deprived, the body has more difficulty processing blood sugar and has reduced levels of leptin, an appetite-suppressing hormone. These changes can increase the risk of weight gain and diabetes. Lack of sleep also increases inflammation in the body, which is believed to be an important factor in the development of heart diseases.

(Source) Online International Network