I'm asking because an elderly relative took a tumble getting up from a nap the other day. When we took him to the hospital to get him checked out, the indicated dehydration as a possible contributing factor. But, he drinks five or six full tumbler size glasses of liquid a day at least. Just wanted to know what you guys think. Thanks in advance!
And the "liquid" he drinks shouldn't include pop.
You said he's drinking 5 or 6 tumblers of liquid a day? What kind of liquid? Water? Juice? Vodka? ;-)
Encourage him to drink more water or juice. Sometimes using a straw makes it easier.
Since your relative fell after getting up from a nap it could be that his blood pressure fell a bit when he went from a sitting to standing position. This is called orthostatic hypotension. Next time he wakes up have him sit at the edge of the bed for a minute before standing up.