The typical way of sleeping and waking is that most humans sleep at night and are awake during the day. Circadian rhythms often follow the hours of daylight and dark, and that works for most people. However, everyone knows that one person that likes to stay up until all hours and sleep late, AKA, the night owl. The technical term is "evening types," and for various reasons, some are just more productive and happier in the evening hours, and less able to get up early and be active in the morning.
A new study from researchers at Northwestern University shows that night owls have a higher risk of early death than their happy morning friends. It's not the hours themselves that are entirely the problem, but rather that the rest of society doesn't work well with late nights. Getting up for early classes is extremely difficult for night owls. The risk of premature death was 10% higher in night owls, as was the risk of diabetes, neurological issues, and respiratory illness.