I think it may also be from the medication, and the additional salt we have to have. I drink 8-10 glasses a day, sometimes more. I have never found a soft drink that would take away my thirst like water does.  I also quite often sit down and watch t.v. with a salt shaker and a glass of ice water. I was always told to drink lots of water and extra salt. I even do it in restuarants, and get some pretty stange looks once in a while. So imho, let’em drink all the water they want.