Hi. what could this mean? dr casually said my muscles r becoming increasingly dehydrated but not from lack of fluid intake or elec imbalance.

Doesn't make sense: There is no such condition as muscle dehydration. He or she may have said something else that was misunderstood. You should go back and ask what was meant. Was it possible that what was said was "myotonia" or hypothyroid? Get that straight and then ask what can be done for whatever it is. Oh, and stay hydrated too, just for good measure!