How much water is someone supposed to drink in a day?

Varies: It's hard to put an absolute amount of water necessary. You may hear 6-8 glasses of water a day. I'd prefer water over large volumes of tea or soft drinks, but, actually, as long as you are urinating in adequate amounts, and you feel refreshed and active, you aren't dehydrated. Drink more in the warmer months, of course. If you are thirsty, you are fluid deprived, so drink more water. Good luck.