Since i was a child i've overslept, sometimes 12+ hours a night.. i'm 27 now and still tired all the time and oversleeping. what's my problem?

Blood work needed: See your doctor to check ut your thyroid function and to make sure you are not anemic.

Need to talk to doc: Hypersomnia, or excessive sleepiness, can be due to a variety of reasons. If it has been present since childhood, i would wonder about a chronic condition such as narcolepsy. I would suggest talking to your doctor. A sleep study may be helpful in determining the cause. Good luck!

Need more : Detailed history. You could possibly have thyroid problem, hormone issues, obese or overweight problems sleep apnea, suffer from insomnia or other medical health issues. Best to get with your physician for complete physical examination.