Your sense of balance is controlled by a number of signals that your brain receives from several locations:
Under normal circumstances, Eyes. No matter what your position, visual signals help you determine where your body is in space and how it’s moving.
Sensory nerves. These are in your skin, muscles and joints. Sensory nerves send messages to your brain about body movements and positions.
Inner ear. The organ of balance in your inner ear is the vestibular labyrinth. It includes loop-shaped structures (semicircular canals) that contain fluid and fine, hair-like sensors that monitor the rotation of your head. Near the semicircular canals are the utricle and saccule, which contain tiny particles called otoconia (o-toe-KOE-nee-uh). These particles are attached to sensors that help detect gravity and back-and-forth motion.
For instance, closing your eyes while washing your hair in the shower doesn’t mean you’ll lose your balance. Signals from your inner ear and sensory nerves help keep you upright.Good balance depends on at least two of these three sensory systems working well.
If your central nervous system can’t process signals from all of these locations, if the messages are contradictory, or if the sensory systems aren’t functioning properly, you may experience loss of balance.
Dizziness may have a number of potential causes. These may include:
Vertigo— The false sense of motion or spinning — is the most common symptom of dizziness. Sitting up or moving around may make it worse. Sometimes vertigo is severe enough to cause nausea and vomiting.
Vertigo usually results from a problem with the nerves and the structures of the balance mechanism in your inner ear (vestibular system), which sense movement and changes in your head position. Abnormal rhythmic eye movements (nystagmus) almost always accompany vertigo.
