does anyone know why I constantly keep having heat flashes and when I get them I feel really dizzy…

does anyone know why I constantly keep having heat flashes and when I get them I feel really dizzy and my ears ring and my hands tingle. Do you think it cuz of dehydration? and also throughout the night when I'm sleeping I wake up in the middle of the night because my whole shirt is wet. I never sweat like that, even when its cold at night I still sweat! what's wrong with me? 😢