Glossary

Read more below about terms related to disorders of the body's balance (vestibular) system in the inner ear in both children and adults.

Acoustic neuroma

Tumor, usually benign, that may develop on the hearing and balance nerves and can cause gradual hearing loss, tinnitus, and/or dizziness.

Learn more about acoustic neuroma.

Audiologist

Health care professional trained to evaluate hearing loss and related disorders, including balance (vestibular) disorders and tinnitus, and to rehabilitate individuals with hearing loss and related disorders. An audiologist uses a variety of tests and procedures to assess hearing and balance function and to fit and dispense hearing aids and other assistive devices for hearing.

Balance

Biological system that enables individuals to know where their bodies are in the environment and to maintain a desired position. Normal balance depends on information from the labyrinth in the inner ear, from other senses such as sight and touch, and from muscle movement.

Balance Disorder

Disruption in the labyrinth, the inner ear organ that controls the balance system, which allows individuals to know where their bodies are in the environment. The labyrinth works with other systems in the body, such as the visual and skeletal systems, to maintain posture.

Benign Paroxysmal Positional Vertigo (BPPV)

Balance disorder that results in sudden onset of dizziness, spinning, or vertigo when moving the head.

Learn more about vertigo-associated disorders.

Learn more about Benign Paroxysmal Positional Vertigo (BPPV).

Canalithiasis

The cause of BPPV, where free-floating debris can migrate into a semicircular canal and cause short episodes of vertigo when it moves within the canal.

Learn more about Benign Paroxysmal Positional Vertigo (BPPV).

Cochlea

Snail-shaped structure in the inner ear that contains the organ of hearing.

Learn more about cochlear implants.

Cochlear Implant

Medical device that bypasses damaged structures in the inner ear and directly stimulates the auditory nerve, allowing some deaf individuals to learn to hear and interpret sounds and speech.

Learn more about cochlear implants.

Cupulolithiasis

A variant of BPPV in which the debris is stuck to the cupula of a semicircular canal rather than being loose within the canal.

Learn more about Benign Paroxysmal Positional Vertigo (BPPV).

Disequilibrium

Any disturbance of balance or loss of equilibrium.

Dizziness

Physical unsteadiness, imbalance, and lightheadedness associated with balance disorders.

Learn more about dizziness.

Labyrinth

Organ of balance located in the inner ear. The labyrinth consists of three semicircular canals and the vestibule.

Labyrinthitis

Viral or bacterial infection or inflammation of the inner ear that can cause dizziness, loss of balance, and temporary hearing loss.

Lightheadedness

The description a person uses who is about to faint. Lightheadedness is medically distinct from dizziness and vertigo.

Ménière's Disease

Inner ear disorder that can affect both hearing and balance. It can cause episodes of vertigo, hearing loss, tinnitus, and the sensation of fullness in the ear.

Learn more about Ménière's Disease.

Motion Sickness

Dizziness, sweating, nausea, vomiting, and generalized discomfort experienced when an individual is in motion.

Neurotologist

Otolaryngologists (ear, nose, throat or ENT doctors) who have completed additional training in medical and surgical diseases of the ear, skull base, and related structures, as well as the connections between the ear and the brain.

Nystagmus

Involuntary, alternating, rapid and slow movements of the eyeballs.

Otoconia

Small calcium carbonate crystals that are part of the balance mechanism. In BPPV, these crystals break loose from their normal attachments and are free to tumble around the inner ear.

Otolaryngologist

Physician/surgeon who specializes in diseases of the ears, nose, throat, and head and neck.

Otoliths

Calcium carbonate crystals found in the inner ear. Damage to the otoliths may lead to BPPV.

Ototoxicity

"Ear poisoning" due to drugs or chemicals that damage the inner ear or the vestibulo-cochlear nerve, which sends balance and hearing information from the inner ear to the brain. Ototoxicity may lead to temporary or permanent disturbances of hearing, balance, or both.

Perilymph

The fluid that fills the space between the semicircular canals and vestibule and the surrounding bone.

Physical Therapy

Services aimed at preventing the onset and/or slowing the progression of conditions resulting from injury, disease, and other causes, including balance disorders. Therapists have a master's or doctoral degree from an accredited program in physical therapy. Some physical therapists are certified in vestibular rehabilitation therapy (VRT).

Presyncope

Feeling faint and lightheaded without losing consciousness.

Tinnitus

Sensation of a ringing, roaring, or buzzing sound in the ears or head. It is often associated with many forms of hearing impairment and noise exposure. Additional information about tinnitus is available here.

Learn more about tinnitus.

Download a tinnitus questionnaire.

Vertigo

Perception of movement (either of the self or surrounding objects) that is not occurring or is occurring differently from how it is perceived.

Learn more about dizziness.

Vestibular System

System in the body that is responsible for maintaining balance, posture, and the body's orientation in space. This system also regulates locomotion and other movements and keeps objects in visual focus as the body moves.