Actually it could just be as simple as you just overslept is all! That's completely normal... Happens to everyone! No worries !!!!! it could also just be that maybe you have worn yourself to thin! all depends i suppose on how long this has been going on!however just to be safe, you may want to check n make sure you have no other signs of depression!!!
well, i went to bed late sat, nite slept all day sun.went back to bed at 9pm sun and just now got up at noon on mon. but i am in my 70s have a thyroid condition am depressed on a anti-depressant plus lots of other medical conditions, i suggest you find a internist (dr.) get a work up and try to get some answers. it's not good to sleep your life away, we will all get plenty of sleep in our next life.
it's possible that this person could have a condition called sleep apnea. I found a website that has more information on this. My mom has it, and not in all cases but in some, it can make you sleep longer and sleep almost constantly! Just copy and paste this website to learn more. Hope it helps! http://www.webmd.com/sleep-disorders/sleep-apnea/sleep-apnea