Is it okay to drink a lot of water because of extreme thirst with adrenal issues?

Adrenal issues: U have to be specific about " adrenal issues" , because there can be many different things that can be wrong with the adrenal gland. However based on the nature of this question , it appears it is related tomadrenal insufficiency. If that is the case, then it is extremely important to keep yourself hydrated but preferably with the electrolyte full water not plain water. Gatrorade is a good choice.

Water intake: To avoid water intoxication and dangerous hyponatremia when you have adrenal gland insufficiency you must rely on the advice of your endocrinologist who knows your baseline electrolytes, kidney function and blood pressure. A normal person can process about a quart of fluid per hour, but you shouldn't drink anywhere that near that and may get into problems drinking more than a few quarts per day.