Why am I sleepy all the time?

I can't wake up. when I get up, I could fall asleep anywhere. I get overwhelmed with the need to shut my eyes and sleep. it is very distracting.

It could be a number of medical conditions:
Thyroid, low Hb, low bp, depression, diabeties, etc...

I agree with Lani, it could be any number of things so if it persists, seek medical help.
Rhonda

Assuming that you are healthy, without the inflictions mentioned above, the number of hours you sleep may be a factor too. It is recommended that you get at least 8 hours of sleep a night. Do you sleep less? More? If you are sleeping less, that could be why you are tired all of the time. Sleeping more can make you feel tired too, because it may rob you from your sleep the next night. Some RULES about napping...
1. No napping for more than one hour.
2. No napping after 4:00pm.

A violation of these rules may take away from your next night's sleep. For what it's worth, these rules are based on psychology theory (of which, there are various opinions). Reminding my wife of these rules, while she is napping, is grounds for a war!