INTRODUCTION

"Dizziness" is a nonspecific term often used by patients to describe symptoms. The most common disorders lumped under this term include vertigo, nonspecific "dizziness," disequilibrium, and presyncope. The first and most important step in the evaluation is to fit the patient into one of these more specific categories.

The general approach to dizziness is reviewed here. The evaluation of vertigo and presyncope (the evaluation of which is the same as the syncope evaluation) are discussed in detail separately. (See "Approach to the patient with vertigo" and "Evaluation of syncope in adults".)

GENERAL APPROACH

The reported proportion of patients with various etiologies of dizziness in community surveys [1], primary care setting [2,3], the emergency department [4-8], and the specialized dizzy clinic [9-13] are remarkably similar: approximately 40 percent of dizzy patients have peripheral vestibular dysfunction; 10 percent have a central brainstem vestibular lesion; 15 percent have a psychiatric disorder; and 25 percent have other problems, such as presyncope and disequilibrium (table 1). The diagnosis remains uncertain in approximately 10 percent. The distribution of causes varies with age. The elderly have a higher incidence of central vestibular causes of vertigo (approaching 20 percent), most often due to stroke. Psychiatric conditions and presyncope account for more dizziness in younger individuals.

The patient's description is critical for establishing the etiology of dizziness. In one series, the history was most sensitive for identifying vertigo (87 percent), presyncope (74 percent), psychiatric disorders (55 percent), and disequilibrium (33 percent) [2]. The physical examination generally confirmed but did not make the diagnosis. Positional changes in symptoms, orthostatic blood pressure and pulse changes, observation of gait, and detection of nystagmus were most helpful on physical examination [2]. Most psychiatric disorders were not detected prior to standardized psychological testing using the diagnostic interview schedule (DIS). Not surprisingly, no patients volunteered the likelihood of a psychiatric cause of dizziness.

Asking open-ended questions, listening to the patient's description of his or her symptoms, and checking and gathering additional information from specific questions should allow the clinician to form a hypothesis regarding the type of dizziness. As an example, a patient who says "I nearly blacked out" might be asked "Do you mean you nearly fainted?" An affirmative reply elicits another checking question, "So you felt you were passing out?" Checking the hypothesis by placing the symptom into context, including its time course, provoking and aggravating factors, concurrent symptoms, age, pre-existing conditions, and the findings on physical examination will narrow the differential, and allow the clinician to decide on the need for further testing and/or evaluation.