The human balance system comprises three hierarchically organized sets of apparatus, receptive (labyrinthine, visual and tomato-sensory). integrative (vestibular nuclear, and cerebellar), and perceptive (thalamic and cortical). Dizziness is caused by an
imbalance between above-mentioned systems. Dizziness is one of the most common complaints for which medical attention is sought. However, evaluation of patients with dizziness is not simple at all since dizziness is a much more ambiguous term used for a
broad variety of unfamiliar or unpleasant sensations of altered orientation in space Because the evaluation and management differ markedly depending on the types of dizziness. it is critical to obtaining the correct type of dizziness by careful history
before proceeding with diagnostic studies. Generally. complaints of dizziness can be divided into four categories ; ① vertigo ② syncope or presyncope ③ disequilibrium ④ ill-defined dizziness. Vertigo is a sensation of definite rotation, an illusory
movement of either a self or anenvironment. The feeling may involve the whole body or be limited to the head The vertiginous sensation may be described as rotating. spinning. tilting of swaying. Nausea. vomiting, ataxia and nystagmus, with or without an
oscillopsia often accompany it. The presence of vertigo implies a disturbance of the vestibular system ; either peripheral of central. Syncope or Presyncope implies a sense of impending loss of consciousness, or fainting. This is often accompanied by
facial pallor, cold perspiration, nausea. apprehension and visual dimness. with recovery on lying down It is due to the insufficient blood supply to, or metabolism in, the entire brain. When it is of gradual onset or persists after tying down disorders
of cerebral metabolism such as hypoglycemia should be considered, rather than cardiovascular syncope. Disequillibrium is a sense of imbalance, which occurs only during walking. It is best described as unsteadiness or drunkeness, without vertigo. It is
due to disorders of the motor control system ; apraxia of gait, astacia-abasia parkinsonism, and multisystem atrophy. Ill-Defined Dizziness is vague lightheadedness, giddiness or fear of falling, other than vertigo, syncope or presyncope, or
disequilibrium. This designation includes dizziness that cannot be identified with certainty as any of the other types. It may occur in patients suffering from various psychiatric disorders such as hyperventilation syndrome, anxiety neurosis,
agoraphobia, and depression.
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