Of all the varied symptoms a patient presents to a physician, dizziness is one of the most common as well as one of the most confusing. It is always confusing to the patient. Frequently it is more confusing to the physician. Yet, within certain limits, it is possible to classify dizziness according to recognizable entities. By so doing the physician not only clarifies part of his confusion, but also establishes some basis for rational therapy. The statements, "within certain limits" and "clarifies part of his confusion," are used advisedly, since, regardless of the classification, there will always remain certain patients whose dizziness is never exactly understood and whose treatment must be a regimen of trial and error. This does not imply that classification, so far as it is possible, is of no value. Just the opposite is true. The physician must have certain classifications of established symptom complexes which, when