I'm not on lithium but boy do I get thirsty! I drink mostly water, no soda and only a cup or two of coffee a day. I don't know why I don't like soda anymore---I used to drink up to six cans a day!---but for some reason I lost my taste for it after my husband died and I haven't had one in months.

Anyway, I drink probably three liters of water a day. I'm on a diuretic (water pill) for my blood pressure and I get dried out pretty quick because I'm peeing all day. There are probably other reasons too but I don't know what they are. It's a good habit to be in anyway---water is good for flushing the kidneys and bladder, and it helps with weight loss. I've lost almost 50 pounds since July and attribute some of it to replacing Coke with water.