Dizziness when lying on the bed is related to the change of head position and is considered to be caused by benign paroxysmal positional vertigo, also known as otolithosis, which is a common clinical disease of peripheral vertigo and accounts for about 30% of outpatient visits. This is because the otolith particles in the balance receptors are dislodged, and when the position of the head changes, the dislodged otoliths flow with the lymphatic fluid in the inner ear, stimulating the semicircular canal cell membranes, and the patient will experience episodes of dizziness with visual rotation. When the head position is fixed, the dizziness and visual rotation can be relieved quickly, and when the patient is dizzy, a rotational nystagmus can be observed.