YMMV, but in my parts, most doctors or heath professionals, unless they themselves have faced being in a repetitive dehydrated state, or have a medical issue where they end up chronically dehydrated, will assume a normal blood pressure reflects good hydration state ... it does not. Low blood pressure could indicate dehydration, high blood pressure could be due to dehydration ... but it does not logically follow that a regular blood pressure means hydration levels are all good.