How can you tell if you're dehydrated? am very sick, can't eat or drink anything without feeling like i'm going to puke it up. how can i prevent myself from getting dehydrated?

If : If you can't hold even water down and this lasts long enough, dehydration is inevitable. If you feel really weak, heart racing, dry mouth and skin, mental confusion, then you need to go to the er, you may need IV fluids. Otherwise, as soon as you can tolerate water, gatorade or powerade do so. Also remember once you start eating, begin with bland foods and increase as tolerated. Take care.