Crystals normally occur in the inner ear, but the symptoms that arise when they become dislodged include dizziness and a sense that the room is spinning, a loss of balance, and nausea and vomiting, states Mayo Clinic. This disorder, called benign paroxysmal positional vertigo, or BPPV, is a common cause of vertigo. Despite its dramatic symptoms, BPPV is a fairly benign disease.
The crystals in the otolith organs in the ear make a person sensitive to gravity, says Mayo Clinic. When the crystals dislodge, they can move into the semicircular canals in the ear. This is more likely to happen when the patient is lying down. When the crystals enter the semicircular canal, the semicircular canal overreacts to small changes of position of the patient's head. This is what causes the vertigo.
Doctors do not know why people get BPPV, but it can appear after head trauma, ear surgery or other injuries to the patient's inner ear, according to Mayo Clinic. Some migraine sufferers also suffer from BPPV. The disorder is more common in women and in people over 50.
Though BPPV often resolves on its own, doctors may teach their patients to do canalith repositioning, says Mayo Clinic. This involves slow, deliberate movements of the head that move the crystals out of the semi-circular canals and into the vestibule of the ear.