Starting Feeling Slightly Dizzy This Morning But Thought Nothing Of

starting feeling slightly dizzy this morning but thought nothing of it. Got a sudden hot flash later in day that only lasted a moment. Then after walking into my daughter's room at about 2:30 the whole room started spinning and I started to feel nauseous. I laid down on the floor and closed my eyes. I was OK if I kept my eyes closed but for about an hour, every time I started to get up I'd feel dizzy and nauseous again.