Dizziness

"Dizzy" can describe so many different sensations that the clinician's first priority must be to pin down what each patient means by it. The best way to do this is to ask the patient to describe the feeling(s) without using the word "dizzy." Sometimes it becomes apparent that the patient is, in fact, describing fatigue and weakness, visual difficulty, or anxiety, and such situations must be handled as outlined in Chapters 213, 111, and 202. More often, each subjective sensation of dizziness can be identified more precisely as one of four types of dizziness: vertigo, disequilibrium, presyncope, or lightheadedness. The clinical approach to the dizzy patient depends crucially on distinguishing among these various kinds of dizziness, since the differential diagnosis is peculiar to each type.

Vertigo refers to the illusion of environmental motion, classically described as "spinning" or "whirling." The sense of motion is usually rotatory—"like getting off a merry-go-round"—but it may be more linear—"the ground tilts up and down, like being on a boat at sea." Disorientation in space and some sense of illusory motion are the common denominators here. Vertigo always reflects dysfunction at some level of the vestibular system, and these problems are discussed in Chapter 123.

Disequilibrium represents a disturbance in balance or coordination such that confident ambulation is impaired. Symptomatically, some such patients clearly profess that "the problem is in my legs," but others feel "dizzy in the head, too." Common to all patients with disequilibrium is the perception that ambulation either causes the problem or clearly makes it worse. Observation of the patient's gait and a careful neurologic examination are thus essential in evaluating this type of dizziness.

(Pre)syncope means that the patient senses impending loss of consciousness. When the patient has, in fact, experienced true syncope (actual loss of consciousness), considerations in Chapter 12 apply. When the patient has not ever actually lost consciousness, the complaint "I feel like I will pass out" should be viewed skeptically, since other types of dizziness may be so described. In such circumstances, the approach to syncope in Chapter 12 may or may not be pertinent.

Lightheadedness is very difficult to describe without using the word "dizzy," but this verbal imprecision is, in fact, very helpful to the clinician. Lightheadedness refers to a sensation "in the head" that is clearly not vertiginous or presyncopal, and that is not invariably related to ambulation. This vague "negative definition" emphasizes that the lightheaded patient's description is always hazily imprecise, and even articulate patients are frustrated by the request to describe the feeling without saying "dizzy." Some describe "floating" or feeling "like my head is not attached to my body," being "high," or "giddy." Many will search for a better description but finally concede, "I just feel dizzy, that's all."