These attacks of sudden, short-lasting dizziness due to lying down in bed and changing head position, accompanied with intense reactions like nausea, vomit, pale skin, sweating, and sometimes diarrhea, are known as benign paroxysmal positional vertigo.
Do you often feel dizzy and unsteady when you tip your head back to look up?
Have you noticed that this can happen for a period than stop and reappear again?