What causes you to feel tired?

Not getting enough sleep makes me feel tired.

a desire to escape

Yeah, my sleep schedule is so beyond pathetic that I had to revise my schedule around it. At the mere age of twelve, I was a full-blown insomniac.
Since January, I’ve been attending a night school. I go to school from 4–9, Monday-Thursday. The benefits are mind-blowing, but it certainly isn’t a schedule for everyone.

To answer your question, I rarely feel tired. I jump from energetic to down downright exhausted.

Too much caffeine… it works during the day, but it makes me soooo tired in the mornings until I can get my fix again. But I love-love-love-love coffee. :)

A really good, hard workout leaves me energized…. and then killed again the following morning.

Really frustrating interpersonal situations. I get agitated at first, then throw the back of my hand over my forehead and flop over. That shit makes me tired.

@Macaulay funny that you say that.. as college progressed the classes I took started later and later and later.. to go along with the fact that I don’t fall asleep til late usually. I had a 9 am freshman year.. now they’re pushing two o’clock. :)

Rainy or dreary weather, being too warm, bored with no alternative (as in class), eating too much sugar (yes, it’s a buzz, but it’s a big drop after that), reading something that is necessary but of zero interest to me, arguments that seem to have no end… I feel tired a lot.

Shit, maybe I should try to actually answer the question——

I recall reading somewhere that 70% of our cell regenerative (read: healing) function happens during stage 4 sleep, or deeper sleep. The remaining 30% occurs during lighter sleep and continually through your waking hours. Cells die off regularly; they must be replaced.

Maybe if you are not replacing them at a rate that your body is satisfied with, your body will tell you to take a nap or go to sleep to play catch-up? That would be my guess.

I guess that in intuitive terms, being tired just means your brain needs rest to regain its strength after having worked for a long time.

I’m going to speculate that this need for recovery could mean that everyday though puts stress on the brain that does minor damage that needs to be rebuilt (much like using a muscle a lot causes tiny rips that are restored gradually, which is how muscles grow), or maybe it depletes some sort of resource (i.e. nutrients) that the brain then needs to gather again in sufficient amounts to be able to function properly again. Or it could be the opposite; that brain activity produces some sort of waste product that needs to be gotten rid of. Or a combination of those things.

Or maybe there’s some other explanation that hasn’t occurred to me yet.

Watching too much tv makes me feel tired

My body and brain burning more oxygen than I can breath. I think when we’re bored, our brains start slipping into shut-off mode. Fighting it makes it even worse.

Also the rain or any thoughts of coziness.

stress… too many things running at the same time in my head…

Aside from poor sleep, could be not enough drinking water, too much sugar in your system or waiting too long to eat between meals.

In a classroom situation, or at work, if my mind is not engaged I tend to get sleepy.

Part of it may be the temperature in the room, or the amount of time after eating combined with an idle mind. Also, if your professor has a monotone voice, that could lull you to sleep.

DEPRESSION!

Boredom, a good cry, and a dry textbook.

Fatigue usually makes me tired.

I just wish I could get tired at the right damn time. Night, for example.

I get tired when I’m too warm, when I’m inactive, after I’ve eaten, and when it’s very overcast. The last one is due to zeitgebers (external light/dark clues from nature that indicate when it is time to sleep) that influence our circadian rhythms. You can get tired when you’ve eaten because of chemicals in food (ie tryptophan in turkey), and if you’re too warm, your body may want to fall asleep to lower your heart rate, which will cause your internal temperature to go down. That’s one reason why it’s good to sleep when you’re sick. If you’re bored/inactive, I guess your body might figure that if you’re not doing anything else more productive, you might as well be sleeping.

stress, depression, and not getting enough sleep!
pretty much what everyone else said, hah.

lack of sleep, boredom, getting drunk all the time

look up hypersomia aswell on wikipedia.org….that seems to be my problem at the minute…im looking it up now in class cause im tired…despite the fact i had (1,2…) 10 hours sleep, which is more than i usually get during termtime…ive always had trouble getting to sleep, catching up on it doesnt seem to help either