Vestibular System

What is the vestibular system?

The vestibular system includes sensory organs in your inner ear that help you maintain your sense of balance. We’re constantly in motion, and so is the world around us. The vestibular system, when it’s working, helps your body understand how you’re moving and how things around you are moving to help maintain your balance or steadiness.

The vestibular system includes the:

• Peripheral vestibular system. The five organs within your inner ear that sense information your body needs to maintain balance — like your posture, position and movement. Usually, when people say “vestibular system,” they mean the balance organs in your inner ear.
• Central vestibular system. The parts of your central nervous system (CNS) that process balance signals that are sent from the vestibular organs within your inner ear.

What does the vestibular system do?

Your vestibular system is a key part of a complex sensory system that keeps you in balance. Walking, running and even remaining upright without falling are all activities you can do thanks to your vestibular system.

Vestibular organs inside your inner ear sense your head movements and send this information to your brain. The movements provide information about your position and orientation within your surroundings. Your brain integrates this data with sensory information from your eyes, muscles and joints. Your eyes help you orient based on what you see, while your muscles and joints provide sensory information as they make contact with your surroundings.

Based on these three inputs (vestibular system + eyes + muscles and joints), your brain sends signals that tell your body how to remain in balance.

Vestibular system reflexes

Your vestibular system isn’t just one of three separate sensory inputs, though. It works closely with your eyes, muscles and joints to coordinate balance functions automatically. Two primary reflexes allow this:

• Vestibulo-ocular reflex (VOR). Your eyes and vestibular system work together so you can maintain your gaze even when you’re in motion. Imagine running toward a target. Although you’re moving, your eyes can remain fixed on where you’re going. Or your vision isn’t bouncing while you run. This happens because of your VOR, or your eyes moving opposite of your head to maintain your gaze. Without it, you’d likely become disoriented and fall.
• Vestibulospinal (VS) reflex. Your muscles also automatically adapt to changes in your vestibular system. Imagine you’re walking on uneven terrain. Your vestibular system detects changes in your position with each subtle head movement. The VS reflex causes your body weight to shift in response, so you don’t stumble.

Where is the vestibular system located?

Your vestibular system organs are inside your inner ear. Your inner ear contains your cochlea, which helps you hear. A separate part of the inner ear called the vestibular labyrinth contains your five vestibular organs (also called the “vestibular apparatus”).

These organs sense your head’s position and send signals to the parts of your brain involved in helping you maintain your balance.

What are the parts of the vestibular system?

The vestibular apparatus within your inner ear includes five vestibular organs:

• Three semicircular canals.
• Two otolith organs.

The vestibular labyrinth housing these organs contains a fluid called endolymph and tiny hair cell sensory receptors. When your head moves, the endolymph shifts, causing the hair cells to shear or move. As a result, the hair cells send sensory information about your movement to your brain. The nerve signals travel via an important structure called the vestibular nerve (vestibular-cochlear nerve or the 8^th cranial nerve).

Semicircular canals

Your semicircular canals are three tubes inside your inner ear that detect rotational head movements. They’re the:

• Superior canal. Detects up and down head movements (like nodding “yes”).
• Horizontal canal. Detects left to right head movements (like shaking your head “no”).
• Posterior canal. Detects side-to-side movements (like tilting your head toward either shoulder).

Each canal ends in a structure called an ampulla. The ampulla contains hair cells that extend into a gelatin-like substance called cupula. When you move your head, the endolymph inside your semicircular canals shifts, causing the hair cells inside the cupula to shift, too. The movement triggers the release of nerve signals that communicate your head’s position to your brain.

Otolith organs

Your otolith organs are two chambers that detect linear movements (those related to gravity). They’re the:

• Utricle. Detects horizontal motion (forward or back, like being in a moving car).
• Saccule. Detects vertical movement (up or down, like being in a moving elevator).

Each otolith organ houses a structure called the macula. The macula includes hair cells that extend into a gelatin-like substance that’s filled with calcium crystals called “otoconia.” When you’re in motion, the otoconia inside your otolith organs shift. This causes the hair cells to shift, as well. This shearing triggers the release of nerve signals that travel to your brain.

What conditions and disorders affect the vestibular system?

The most common peripheral (inner ear) vestibular disorders include:

• Benign paroxysmal positional vertigo.
• Labyrinthitis.
• Ménière’s disease.
• Vestibular neuritis.

The most common central (CNS) vestibular disorders include:

• Mal de débarquement syndrome (MdDS).
• Persistent postural-perceptual dizziness (PPPD).
• Vestibular migraines.

Common signs or symptoms of a problem with the vestibular system

The most common symptoms of a balance issue are dizziness and vertigo. Although both involve feeling unsteady on your feet or in your body, they’re not the same.

If you’re dizzy, you may feel:

• Woozy.
• Light-headed.
• Disoriented.

With vertigo, you may feel:

• As if you’re spinning (even when you’re not).
• As if the world is spinning around you.

You may have other symptoms that impact your hearing and vision depending on the specific vestibular condition. After all, your vestibular system is closely linked with your eyes and ears (since the primary organs are in your inner ear). Sometimes, issues overlap.

Common tests to check the health of the vestibular system

Vestibular testing is the most common assessment healthcare providers use to diagnose vestibular conditions. It includes several tests that check the health of your vestibular organs. Most focus on how well your eyes and vestibular system are working together to help you maintain balance (VOR).

You may need blood tests to check for infections or imaging procedures to check for structural problems impacting your vestibular system.

What are common treatments for vestibular system conditions?

Most vestibular system conditions require a combination of treatments, including:

• Lifestyle changes to reduce stressors that may trigger episodes of dizziness or vertigo.
• Vestibular physical therapy to help reduce symptoms, strengthen the VOR/impaired structures, or complete repositioning maneuvers.
• Medications for an infection or to help ease vertigo symptoms, like nausea.
• Surgery to repair inner ear structures causing issues.

How can I keep my vestibular system healthy?

Most causes of vestibular disorders aren’t preventable. But you can care for your vestibular system (and yourself) by getting treated as soon as possible at the first sign of an issue.

For example, even conditions that eventually get better (like inner ear infections) can damage the delicate sensory hair cells inside your ear. Once they’re damaged, these cells don’t repair themselves.

How do you balance the vestibular system?

Vestibular rehabilitation therapy can help you better coordinate the parts of your vestibular system. Working with a healthcare provider who specializes in vestibular disorders can help train your brain to respond more effectively to the messages it’s getting from the vestibular organs within your inner ear.

A note from Cleveland Clinic

When you hear the word “vestibular,” think of a simpler one: balance. Your sense of balance may not be as well-known as your senses of taste, touch, vision, hearing or smell — but it’s just as important. The vestibular organs within your inner ear do important work by helping you remain steady on your feet. Care for your vestibular system by seeing a healthcare provider at the first sign of a vestibular issue like dizziness or vertigo.