Do you mean that you feel dizziness when turning over? If so, you may have a condition called
benign paroxysmal positional vertigo (BPPV). It's one of the most common causes of vertigo — the sudden sensation that you're spinning or that the inside of your head is spinning.
Benign paroxysmal positional vertigo causes brief episodes of mild to intense dizziness. Benign paroxysmal positional vertigo is usually triggered by specific changes in the position of your head. This might occur when you tip your head up or down, when you lie down, or when you turn over or sit up in bed.