Dizziness

Vertigo is the illusion of movement of either the body or environment. This symptom is often described using terms such as spinning, turning, reeling, or any other depiction of movement. Most commonly, vertigo is due to a problem within the inner ear or the vestibular nerve, which is the nerve that helps to maintain balance. Benign positional vertigo, an illness caused by free-floating particles within the inner ear, can be diagnosed by its characteristic symptoms. With this illness, vertigo is provoked by changing position or moving the head, and symptoms usually last thirty seconds to several minutes. On the other hand, vestibular neuronitis, also called acute labyrinthitis or vestibulitis, usually causes a single episode of vertigo that may last from one day to several months. Vestibular neuronitis is thought to be caused by a viral infection. Another illness of the inner ear, Meniere's disease, can be differentiated by its long duration and associated hearing loss. Sometimes, vertigo can be caused by a central problem within the brain, such as a stroke.

The term presyncope refers to near fainting. People describe this as "blacking out" or "nearly fainting." There are many causes of presyncope, such as abnormal heart rhythms, medication, problems with internal blood pressure control (carotid hypersensitivity), and volume depletion. Not uncommonly, presyncope will occur without an identifiable underlying medical illness or specific cause.

The two remaining subtypes of dizziness, dysequilibrium and light-headedness, are less specific and in many cases the cause of these complaints cannot be accurately determined. The term dysequilibrium refers to a feeling of imbalance. The subtype of light-headedness is reserved for symptoms of dizziness that do not fit into any of the three other categories.

Although these subtypes of dizziness account for some causes of dizziness, it is not always possible to classify symptoms in a given individual. Often, one simple cause cannot be found to explain why dizziness is occurring and frequently there are several contributing causes, none of which alone would pose a problem. In combination, however, these factors produce the sensation of dizziness. Common contributors to dizziness include medication, impaired balance, heart disease, visual impairment, hearing loss, blood pressure that drops upon standing (i.e., orthostatic hypotension), decreased sensation in the feet, and chronic medical problems. Other cited causes of dizziness include psychiatric problems, hyperventilation, seizures, and disorders of the neck.