What causes dizziness?

The vestibular system within the ear is the organ responsible for balance in humans. It is located in the inner part of each ear and provides the brain with information regarding movement and position in space. Dizziness is described as a sense of falling or loss of control. Whenever there is a sensation of spinning it is known as vertigo. Dizziness and vertigo can occur due to a disruption of the inner ear mechanism. Damage to the mechanism can also result in visual disturbances, nausea and vomiting. This condition can be very disruptive causing difficulty in walking and increased risk of falls and other accidents.

The main inner ear disorders leading to the symptom of dizziness and vertigo are: Benign Paroxysmal Positional Vertigo (BPPV), Meniere's Disease, and Acoustic Neuroma (tumor on the hearing nerve). Complications of ear surgery can also result in dizziness. Other common causes of balance disorders are head trauma, vertebral artery insufficiency, and other health problems.

Until recently, very little could be done to improve the balance of people with inner ear disorders. However, treatment has now become available to improve, if not cure, many of the problems associated with the vestibular organ.

It can also be a common side effect of medications. It is caused by toxic chemicals and fumes and by injuries to the head or neck. Sometimes the problem is in the central nervous system—the brainstem, brain or inner ear. Everyone knows that the ears sense sound, but not everyone knows that ears also sense head movements and that ear disorders can make you dizzy or unbalanced.

Although your balance system is located primarily in the inner ear, it is connected with the brain and brainstem, the eyes, and the sensory nerves throughout your body. Each of these centers sends and receives messages that permit you to maintain your balance. When a disorder is present, these messages cause you to feel abnormal dizziness or an imbalance.

One clearly measurable sign of what’s going on with your balance system is a rapid, involuntary eye movement called nystagmus. By stimulating the nervous system in various ways that usually affect balance, and then carefully measuring your eye movements, a hearing and balance specialist can learn much about any abnormalities in your vestibular system.

This procedure is called VNG or ENG. VNG stands for videonystagmography, which tracks eye movement through video recording techniques. ENG, or electronystagmography, is the recording of eye movements from electrical signals rather than video recording. VNG being the most technologically advanced.

Dizziness-causing ear disorders include fluid imbalances, infections, high blood pressure, anemia and degenerative diseases. The most common of these has a long name—benign paroxysmal positional vertigo. It occurs when tiny crystals get lodged in the wrong part of the inner ear and it can cause severe dizziness or imbalance, especially when you lie down in bed. The crystals that cause the distorted information can be relocated within the inner ear system by a series of head movements done by a specialist. The crystals then settle to a section of the inner ear where they tend not to move and therefore no longer cause the disturbance. Again, careful assessment and correct diagnosis are most important. The treatment is not difficult but needs to be done by a medical professional.