Q. Please explain positional vertigo. Two of my siblings have woken up in the morning with it. What do you do if you experience it?

A. Positional vertigo is a common type of dizziness that can be treated with a simple maneuver.

Vertigo is an illusory sensation of motion that is often accompanied by intense nausea.

Benign paroxysmal positional vertigo, or B.P.P.V., is the medical term for positional vertigo. It is important to use this term, as there are other types of vertigo with different causes and treatments.

B.P.P.V. is caused by microscopic “stones” that are present on the ends of hair cells in the ear canal and that help you maintain your balance. Vertigo occurs when these stones break off and move from the body of the inner ear into its semicircular canals, which determine our perception of three-dimensional space. This usually occurs as a result of aging or head trauma.