Normally, crystals in the inner ear let a person detect and respond to gravity, according to Mayo Clinic. This allows the smooth movement of the head up and down and from side to side. Normally, these crystals are contained in the otolith organs called the saccule and utricle, according the University of Minnesota Medical School Duluth.
Sometimes, the crystals escape these otolith organs and drift into one of the ear's semicircular canals, as Mayo Clinic explains. This causes the semicircular canals to become so sensitive to changes in the position of a patient's head that he becomes dizzy from movements that didn't make him dizzy before. This condition is called benign paroxysmal positional vertigo, or BPPV. Other symptoms of BPPV include feeling that the room is spinning, loss of balance, nausea and vomiting. Sometimes, the patient experiences abnormal eye movements.
Fortunately, BPPV usually goes away on its own because the brain eventually adjusts to the new sensitivity in the inner ear, notes WebMD. However, a physician might perform either the Epley or Semont maneuvers on a patient to treat his BPPV. These maneuvers move the crystals in the ear around and relieve the symptoms of BPPV. They can also be performed at home by the patient.