Epidemiology of Dizziness

Timothy C. Hain, MD Page last modified: December 29, 2007

Relatively little is known about the precise incidence and prevalence of dizziness in the general population. It is generally accepted to be common, although not so common as diabetes or heart disease, and to increase with age. To deal with it rationally, one must break dizziness down into categories:

• Inner ear dizziness (otologic)
• Medical dizziness
• Neurological dizziness
• Psychiatric dizziness
• Undiagnosed dizziness

Overall

A rough estimate of the overall incidence of dizziness can be obtained from survey studies. The NHIS (US national health interviews survey) provided data. About 300,000 persons were affected in the United states over 1986-1988 per year with dizziness and vertigo. About 26% of them were unable to work, accounting for an economic impact of about 75,000 persons per year unable to work due to dizziness and vertigo. If we assume that this causes $30,000 of economic damage each year per person, this means that dizziness/vertigo costs the nation roughly 2.25 billion $ each year.

A less precise method of measuring it is to just look at how many patients present to medical clinics. Dizziness is the primary complaint in 2.5% all primary care visits = 8 million/year visits (Sloane, 1989). There are substantial otologic, neurologic, general medical, and psychiatric/undiagnosed causes of vertigo (see below).

Proportions

The proportion of patients in each category is known to some extent, from clinics that have reported differential diagnosis.

• Inner ear disorders seem to account for roughly 30-50% of all dizziness.
• Medical disorders, between 5 and 30%
• Neurological disorders, between 2 and 30%
• Psychiatric disorders, between 15 and 50%
• Undiagnosed, up to 50%.

TABLE 1: DIAGNOSES IN DIZZY PATIENTS.

• 1. Madlon-Kay, 1985. Unlocalized category included vasovagal, psychogenic, unknown.
• 2. Nedzelski, Barber, McIlmoyl, 1985. Unlocalized category included head injury.
• 3. Drachman and Hart, 1972. Unlocalized category included hyperventilation, psychogenic, "excessive awareness of normal sensation", unknown.
• 4. Bath et al, 2000.
• 5. Guilemany, 2004

Table 1 summarizes the results of several studies of diagnoses obtained in dizzy patients according to the setting where the patients were seen, and shows that dizziness is multifactorial.  No specialty, be it otology, neurology, internal medicine or psychiatry, has a clear preponderance of dizzy  patients.

OTOLOGIC

According to Neuhauser and others (2005), vestibular vertigo is common in the general population, affecting more than 5% of adults in 1 year. The frequency and health care impact of vestibular symptoms at the population level have been underestimated. We agree with this assessment.

TABLE 2: CAUSES OF OTOLOGIC DIZZINESS

Diagnosis                                             Percent

• BPPV                                            49
• Meniere's disease                         18.5
• Unilateral Vestibular paresis        13.5
• Bilateral Vestibular paresis          8
• Middle Ear Dysfunction                6
• Fistula                                           5

n = 119

Source: Northwestern Memorial Hospital Neurotology clinic, 1992-1993

Otologic vertigo accounts for 24-41% of all dizziness (see Table 1).  Unsurprisingly, otologic vertigo is especially common in the otology subspecialty setting. 

Table 2 shows how the causes ear dizziness distribute. The most important feature of the table 2 above is the very high proportion of these patients in the first three categories. The incidence of BPPV rises steadily with age, while the incidence of other conditions either remains steady (e.g. Meniere's disease and Vestibular Neuritis), or rises but never gets very large (e.g. Bilateral Vestibular Paresis). Note that tumors such as Acoustic Neuroma are simply so rare that they don't contribute substantially to otologic dizziness.

NEUROLOGICAL DIZZINESS

Table 3: CAUSES OF NEUROLOGICAL DIZZINESS

Diagnosis                                                         Percent

• Stroke and TIA                                              35
• Vertebrobasilar migraine                              16
• Nystagmus (i.e. congenital)                           8
• Sensory ataxia                                               7
• Basal ganglia dysfunction                              4
• Cerebellar ataxia                                           5
• Seizure                                                           3
• Miscellaneous disorders                               22

n = 74

Source: Northwestern Memorial Hospital Neurotology clinic, 1992-1993

Neurological dizziness is loosely defined here as a group of conditions causing dizziness that are usually diagnosed and treated by neurologists. In addition to dizziness associated with dysfunction of the central nervous system, it also includes dizziness or ataxia caused by sensory neuropathy and visual dysfunction.  The incidence of neurological dizziness in the emergency setting is only about 2% (see Table 1).  The incidence in the primary care setting is unknown, but probably also low.  Only neurologists report a substantial proportion of dizzy patients with neurological dizziness, and even in this setting, "neurological" diagnoses account for only about 1/3 of their cases (Drachman and Hart, 1972; Macrae, 1960).

Vertigo in the neurology setting is dominated by vascular causes, combined with a larger number of rarer miscellaneous causes. Stroke and transient ischemic attack, usually involving the brainstem or cerebellum, account for about one third of neurologic dizziness and vertigo attributed to Vertebrobasilar migraine causes another 16% (Table 4) or more (Savundra et al reported 32%).  A variety of miscellaneous causes of dizziness make up the remainder. Vertigo attributed to "miscellaneous" (22%), includes disorders of CSF drainage, multiple sclerosis, the Chiari malformation, cervical vertigo, and conditions accompanied by central positional nystagmus or tremor.

MEDICAL DIZZINESS

Table 4: CAUSES OF "MEDICAL" DIZZINESS

Diagnosis Percentage

• Cardiovascular                                                23-43
  • Hypotension
  • Cardiac arrhythmia
  • Coronary artery disease
• Hypertension
• Infection                                                          4-40
• Medication                                                      7-12
• Hypoglycemia                                                 4-5

n = 40

Source: Madlon Kay, 1985; Herr et al, 1989

General medical diagnoses are assigned to about 33% of cases of dizziness seen in the emergency setting (see Table 1). These include disorders which alter blood pressure, blood sugar, or which are attributed to an infection or medication.  In the primary care setting, medical causes account for a similar fraction of diagnoses. Hypertension, disturbances of blood glucose, and coronary atherosclerosis are the most common diagnoses  (Sloane 1989).  General medical diagnoses are very unusual in specialty settings, associated with only 2% of diagnoses in the otology setting and 5% in the neurotology setting.

Although "psychogenic" dizziness is sometimes lumped together with "unlocalized" cases, it is clear that even when they are rigorously separate that this is a substantial group,    However, it is difficult to be certain in what percentage of patients this is indeed the case. 

UNLOCALIZED DIZZINESS

Unlocalized vertigo includes patients whose symptoms are attributed to a patients whose vertigo is attributed to an event without further definition (such as head trauma) and patients with vertigo and dizziness of unclear origin. Common variants of unlocalized variants include "hyperventilation syndrome", "post-traumatic vertigo," and "nonspecific" dizziness. About 15-25% of dizziness or vertigo falls into this category.

REFERENCES

• Bath AP, Walsh RM, Ranalli P, Tyndel F, Bance M, Mai R, Rutka JA. Experience from a multidisciplinary "Dizzy" clinic. Am J. Otol 21:92-97, 2000
• Drachman D, Hart CW. An approach to the dizzy patient. Neurology 1972;22:323‑334.
• Guilemany, J. M., P. Martinez, E. Prades, et al. (2004). "Clinical and epidemiological study of vertigo at an outpatient clinic." Acta Otolaryngol124(1): 49-52.
• Hain TC. Approach to the Vertigo Patient  In J. Biller (ed). Practical Neurology, Lippincott-Raven, Philadelphia, 1997
• Hain TC, Herdman SJ. Dizziness in the Elderly. (Ed Sage JI, Mark MH) Practical Neurology of the Elderly. Marcel Dekker Pub, New York, NY 1996.
• Herr RD, Zun L, Mathews JJ. A directed approach to the dizzy patient. Annals Emergency Med 1989; 664-672.
• Jonsson, R., E. Sixt, S. Landahl, et al. (2004). "Prevalence of dizziness and vertigo in an urban elderly population." J Vestib Res 14(1): 47-52.
• Kroenke K, Lucas CA, Rosenberg ML, Scherokman B, Herberts JE, Wehrle PA, Boggi JO. Causes of Persistent dizziness. Ann Int Med 1992; 117: 898-904.
• Macrae D. The neurologic aspects of vertigo. Analysis of 400 cases. California Medicine 1960;92:255-259.
• Madlon-Kay DJ. Evaluation and outcome of the dizzy patient. J. Family Practice 1985;109-113.
• Nedzelski JM, Barber HO, McIlmoyl L. Diagnoses in a dizziness unit. J. Otolaryngol 1986;15:101-104.
• Neuhauser, H. K., M. von Brevern, A. Radtke, et al. (2005). "Epidemiology of vestibular vertigo: a neurotologic survey of the general population." Neurology65(6): 898-904.
• Savundra PA, Carroll JD, Davies RA, Luxon LM. Migraine-associated vertigo. Cephalgia 17(4) 505-510, 1997
• Sloane PD. Dizziness in primary care. Results from the national ambulatory medical care survey. J. Family Practice 1989;29:33-38.