What you /were/ doesn't really come into it. If you're feeling crap, being sick the once may well sort you out to a point where you can feel a bit better for the rest of the day. If you're too far gone, it'll feel better for about a minute and then you'll feel as bad again. Drink water, stay away from bright lights and noise and monitors.
If you are drunk be sick before you go to bed, that way you have a better chance of either getting rid of the hangover or have a less bad one. The reason being is that you are getting rid of most of the alcohol in your digestive system.
