Sleeping at night VS sleeping in the daytime. Difference?

[hkhil]

Hi

After many years of bad habit, I now have trouble regulating my sleep times. I would find that every night I would sleep a quarter of an hour or so later, and wake up later too. Eventually, I would end up sleeping in the mornings and waking up around sunset, only to have the system turn around again soon after.

My parents used to say to me when I was small that night means we are standing "upside down" so we are getting "pulled down" and that's bad. Which served its purpose in scaring me back then but there is no such thing as "upside down".

But it is true that sleeping at night and waking in the day gives me more energy. Whenever I stay awake all night until morning, I feel dehydrated and beat - something I don't feel if I sleep at night (even for just a few hours).

Why is that? What's making me exhausted when I stay up at night? When the sun rises, the exhaustion hits me the hardest. As far as I know, there is no scientific reason for this?

So is it bad to be nocturnal? Even if I do get 8 hours sleep every "day"?

Hope it's not TOO unhealthy.

 

[Astronuc]

Humans are by nature diurnal. The body has adapted to sunlight, and people need a certain amount of sunlight. Too little sunlight can apparently cause a slight depression - seasonal affective disorder (SAD).

Human eyes are adapted to daylight, not the darkness of night.

However, some people adapt to being awake at night, and sleep during the day.

Possible the fatigue one feels in the morning corresponds with the time at which the brain would be in deep state of sleep. This would also correspond to about the time when one is dreaming. The brain needs to sleep.

http://en.wikipedia.org/wiki/Sleep