Dizziness is an imprecise term patients often use to describe various related sensations, including
Faintness (a feeling of impending syncope)
Feeling of imbalance or unsteadiness
A vague spaced-out or swimmy-headed feeling
A spinning sensation
Vertigo is a sensation of movement of the self or the environment when there is no actual movement. Usually the perceived movement is rotary—a spinning or wheeling sensation—but some patients simply feel pulled to one side. Vertigo is not a diagnosis—it is a description of a sensation.
Both sensations may be accompanied by nausea and vomiting or difficulty with balance, gait, or both.
Perhaps because these sensations are hard to describe in words, patients often use “dizziness,” “vertigo,” and other terms interchangeably and inconsistently. Different patients with the same underlying disorder may describe their symptoms very differently. A patient may even give different descriptions of the same “dizzy” event during a given visit depending on how the question is asked. Because of this discrepancy, even though vertigo seems to be a clearly delineated subset of dizziness, many clinicians prefer to consider the two symptoms together.
However they are described, dizziness and vertigo may be disturbing and even incapacitating, particularly when accompanied by nausea and vomiting. Symptoms cause particular problems for people doing an exacting or dangerous task, such as driving, flying, or operating heavy machinery.
Dizziness accounts for about 5 to 6% of physician visits. It may occur at any age but becomes more common with increasing age; it affects about 40% of people over age 40 at some time. Dizziness may be temporary or chronic. Chronic dizziness, defined as lasting > 1 month, is more common among older people.
Pathophysiology of Dizziness and Vertigo
The vestibular system is the main neurologic system involved in balance. This system includes
The vestibular apparatus of the inner ear
The 8th (vestibulocochlear) cranial nerve, which conducts signals from the vestibular apparatus to the central components of the system
The vestibular nuclei in the brain stem and cerebellum
Disorders of the inner ear and 8th cranial nerve are considered peripheral disorders. Those of the vestibular nuclei and their pathways in the brain stem and cerebellum are considered central disorders.
The sense of balance also incorporates visual input from the eyes and proprioceptive input from the peripheral nerves (via the spinal cord). The cerebral cortex receives output from the lower centers and integrates the information to produce the perception of motion.
Perception of stability, motion, and orientation to gravity originates in the vestibular apparatus, which consists of
The 3 semicircular canals
The 2 otolith organs—the saccule and utricle
Rotary motion causes flow of endolymph in the semicircular canal oriented in the plane of motion. Depending on the direction of flow, endolymph movement either stimulates or inhibits neuronal output from hair cells lining the canal. Similar hair cells in the saccule and utricle are embedded in a matrix of calcium carbonate crystals (otoliths). Deflection of the otoliths by gravity stimulates or inhibits neuronal output from the attached hair cells.
Etiology of Dizziness and Vertigo
There are numerous structural (trauma, tumors, degenerative), vascular, infectious, toxic (including drug-related), and idiopathic causes (see table Some Causes of Dizziness and Vertigo Some Causes of Dizziness and Vertigo ), but only a small percentage of cases are caused by a serious disorder.
The most common causes of dizziness with vertigo involve some component of the peripheral vestibular system:
Other causes include a central vestibular disorder (most commonly migraine), a disorder with a more global effect on cerebral function, a psychiatric disorder, or a disorder affecting visual or proprioceptive input. Sometimes, no cause can be found.
The most common causes of dizziness without vertigo are less clear cut, but they are usually not otologic and probably are
Multifactorial or idiopathic
Nonneurologic disorders with a more global effect on cerebral function sometimes manifest as dizziness and rarely as vertigo. These disorders typically involve inadequate substrate (eg, oxygen, glucose) delivery caused by hypotension, hypoxemia Oxygen Desaturation Patients without respiratory disorders who are in the intensive care unit (ICU)—and other patients—may develop hypoxia (oxygen saturation 90%) during a hospital stay. Hypoxia in patients with... read more , anemia Evaluation of Anemia Anemia is a decrease in the number of red blood cells (RBCs—as measured by the red cell count, the hematocrit, or the red cell hemoglobin content). In men, anemia is defined as hemoglobin 14... read more , or hypoglycemia Hypoglycemia Hypoglycemia unrelated to exogenous insulin therapy is an uncommon clinical syndrome characterized by low plasma glucose level, symptomatic sympathetic nervous system stimulation, and central... read more ; when severe, some of these disorders may manifest as syncope Syncope Syncope is a sudden, brief loss of consciousness with loss of postural tone followed by spontaneous revival. The patient is motionless and limp and usually has cool extremities, a weak pulse... read more . Additionally, certain hormonal changes (eg, as with thyroid disease Overview of Thyroid Function The thyroid gland, located in the anterior neck just below the cricoid cartilage, consists of 2 lobes connected by an isthmus. Follicular cells in the gland produce the 2 main thyroid hormones... read more , menstruation, pregnancy) can cause dizziness. Numerous central nervous system-active drugs can cause dizziness independent of any toxic effect on the vestibular system.
Occasionally, dizziness and vertigo may be psychogenic. Patients with persistent perceptual postural dizziness (PPPD, dizziness that lasts for over three months with no clinical explanation for its persistence), panic disorder Panic Attacks and Panic Disorder A panic attack is the sudden onset of a discrete, brief period of intense discomfort, anxiety, or fear accompanied by somatic and/or cognitive symptoms. Panic disorder is occurrence of repeated... read more , hyperventilation syndrome Hyperventilation Syndrome Hyperventilation syndrome is anxiety-related dyspnea and tachypnea often accompanied by systemic symptoms. Hyperventilation syndrome most commonly occurs among young women but can affect either... read more , anxiety Overview of Anxiety Disorders Everyone periodically experiences fear and anxiety. Fear is an emotional, physical, and behavioral response to an immediately recognizable external threat (eg, an intruder, a car spinning on... read more , or depression Depressive Disorders Depressive disorders are characterized by sadness severe enough or persistent enough to interfere with function and often by decreased interest or pleasure in activities. Exact cause is unknown... read more may present with complaints of dizziness.
In older patients, dizziness is often multifactorial secondary to drug adverse effects and age-diminished visual, vestibular, and proprioceptive abilities. Two of the most common specific causes are disorders of the inner ear: benign paroxysmal positional vertigo Benign Paroxysmal Positional Vertigo In benign paroxysmal positional vertigo, short ( 60 seconds) episodes of vertigo occur with certain head positions. Nausea and nystagmus develop. Diagnosis is clinical. Treatment involves canalith... read more and Meniere disease Meniere Disease Meniere disease is an inner ear disorder that causes vertigo, fluctuating sensorineural hearing loss, and tinnitus. There is no reliable diagnostic test. Vertigo and nausea are treated symptomatically... read more .
Evaluation of Dizziness and Vertigo
History of present illness should cover the sensations felt; an open-ended question is best (eg, “Different people use the word ‘dizziness’ differently. Can you please describe as thoroughly as you can what you feel?”). Brief, specific questioning as to whether the feeling is faintness, light-headedness, loss of balance, or vertiginous may bring some clarity, but persistent efforts to categorize a patient’s sensations are unnecessary. Other elements are more valuable and clear-cut:
Severity of initial episode
Severity and characteristics of subsequent episodes
Symptoms continuous or episodic
If episodic, frequency and duration
Triggers and relievers (ie, triggered by head/body position change)
Associated aural symptoms (eg, hearing loss, ear fullness, tinnitus)
Severity and related disability
Is the patient having a single, sudden, acute event, or has dizziness been chronic and recurrent? Was the first episode the most severe (vestibular crisis)? How long do episodes last, and what seems to trigger and worsen them? The patient should be asked specifically about movement of the head, arising, being in anxious or stressful situations, and menses. Important associated symptoms include headache, hearing loss, tinnitus, nausea and vomiting, impaired vision, focal weakness, and difficulty walking. The severity of impact on the patient’s life should be estimated: Has the patient fallen? Is the patient reluctant to drive or leave the house? Has the patient missed work days?
Review of systems should seek symptoms of causative disorders, including symptoms of upper respiratory infection (inner ear disorders); chest pain, palpitations, or both (heart disease); dyspnea (lung disease); dark stools (anemia caused by gastrointestinal blood loss); and weight change or heat or cold intolerance (thyroid disease).
Past medical history should note presence of recent head trauma (usually obvious by history), migraine, diabetes, heart or lung disease, and drug and alcohol abuse. In addition to identifying all current drugs, drug history should assess recent changes in drugs, doses, or both.
Examination begins with a review of vital signs, including presence of fever, rapid or irregular pulse, and supine and standing blood pressure (BP), noting any drop in BP on standing up ( orthostatic hypotension Orthostatic Hypotension Orthostatic (postural) hypotension is an excessive fall in blood pressure (BP) when an upright position is assumed. The consensus definition is a drop of > 20 mm Hg systolic, 10 mm Hg diastolic... read more ) and whether standing provokes symptoms. If standing does provoke symptoms, postural symptoms should be distinguished from those triggered by head movement by returning the patient supine until symptoms dissipate and then rotating the head.
The otologic and neurologic examinations are fundamental. Specifically, with the patient supine, the eyes are checked for presence, direction, and duration of spontaneous nystagmus Nystagmus . Direction and duration of nystagmus and development of vertigo are noted.
A gross bedside hearing test Physical examination Worldwide, about half a billion people (almost 8% of the world's population) have hearing loss ( 1). More than 10% of people in the US have some degree of hearing loss that compromises their... read more is done, the ear canal is inspected for discharge and foreign body, and the tympanic membrane is checked for signs of infection or perforation.
Cerebellar function is tested by assessing gait and doing a finger-nose test and the Romberg test (see How to Assess Sensation How to Assess Sensation ). The Fukuda stepping test How to Assess Sensation (marching in place with eyes closed, previously known as the Unterberger test) may be done by specialists to help detect a unilateral vestibular lesion. The remainder of the neurologic examination is done, including testing the rest of the cranial nerves.
The following findings are of particular concern:
Head or neck pain
Loss of consciousness
Focal neurologic deficit
Severe, continuous symptoms for > 1 hour
Interpretation of findings
Traditionally, differential diagnosis has been based on the exact nature of the chief complaint (ie, distinguishing dizziness from light-headedness from vertigo). However, the inconsistency of patients’ descriptions and the poor specificity of symptoms make this unreliable. A better approach places more weight on the onset and timing of symptoms, the triggers, and associated symptoms and findings, particularly otologic and neurologic ones.
Some constellations of findings are highly suggestive (see table Some Causes of Dizziness and Vertigo Some Causes of Dizziness and Vertigo ), particularly those that help differentiate peripheral from central vestibular disorders.
Peripheral: Ear symptoms (eg, tinnitus, fullness, hearing loss) usually indicate a peripheral disorder. They are typically associated with vertigo and not generalized dizziness (unless caused by uncompensated peripheral vestibular weakness). Symptoms are usually paroxysmal, severe, and episodic; continuous dizziness is rarely due to peripheral vertigo. Loss of consciousness is not associated with dizziness due to peripheral vestibular pathology.
Central: Ear symptoms are rarely present, but gait/balance disturbance is common. Nystagmus is not inhibited by visual fixation.
Patients with a sudden, ongoing attack should have pulse oximetry and fingerstick glucose test. Women should have a pregnancy test. Most clinicians also do an ECG. Other tests are done based on findings (see table Some Causes of Dizziness and Vertigo Some Causes of Dizziness and Vertigo ), but generally gadolinium-enhanced MRI is indicated for patients with acute symptoms who have headache, neurologic abnormalities, or any other findings suggestive of a central nervous system etiology.
Patients with chronic symptoms of central vestibular pathology should have gadolinium-enhanced MRI to look for evidence of stroke Overview of Stroke Strokes are a heterogeneous group of disorders involving sudden, focal interruption of cerebral blood flow that causes neurologic deficit. Strokes can be Ischemic (80%), typically resulting... read more , multiple sclerosis Multiple Sclerosis (MS) Multiple sclerosis (MS) is characterized by disseminated patches of demyelination in the brain and spinal cord. Common symptoms include visual and oculomotor abnormalities, paresthesias, weakness... read more , or other central nervous system lesions.
Patients for whom results of bedside tests of hearing and vestibular function are abnormal or equivocal should undergo formal testing with audiometry and electronystagmography.
ECG, Holter monitoring for heart rhythm abnormalities, echocardiography, and exercise stress testing may be done to evaluate heart function.
Laboratory tests are rarely helpful, except for patients with chronic vertigo and bilateral hearing loss, for whom syphilis serology is indicated.
Treatment of Dizziness and Vertigo
Treatment of dizziness and vertigo is directed at the cause, including stopping, reducing, or switching any causative drugs.
If a vestibular disorder is present and thought to be secondary to active Meniere disease Meniere Disease Meniere disease is an inner ear disorder that causes vertigo, fluctuating sensorineural hearing loss, and tinnitus. There is no reliable diagnostic test. Vertigo and nausea are treated symptomatically... read more or vestibular neuronitis Vestibular Neuronitis Vestibular neuronitis causes a self-limited episode of vertigo, presumably due to inflammation of the vestibular division of the 8th cranial nerve; some vestibular dysfunction may persist. Sometimes... read more or labyrinthitis Purulent Labyrinthitis Purulent (suppurative) labyrinthitis is bacterial infection of the inner ear, often causing deafness and loss of vestibular function. Purulent labyrinthitis usually occurs when bacteria spread... read more , the most effective vestibular nerve suppressants are diazepam (2 to 5 mg orally every 6 to 8 hours, with higher doses given under supervision for severe vertigo) or oral antihistamine/anticholinergic drugs (eg, meclizine 25 to 50 mg three times a day). All of these drugs can cause drowsiness, thereby limiting their use for certain patients. Nausea can be treated with prochlorperazine 10 mg IM four times a day or 25 mg rectally twice a day. Vertigo associated with benign paroxysmal positional vertigo Benign Paroxysmal Positional Vertigo In benign paroxysmal positional vertigo, short ( 60 seconds) episodes of vertigo occur with certain head positions. Nausea and nystagmus develop. Diagnosis is clinical. Treatment involves canalith... read more is treated with the Epley maneuver Epley maneuver: A simple treatment for a common cause of vertigo (otolith repositioning) done by an experienced practitioner. Meniere disease is best managed by an otolaryngologist with training in management of this chronic disorder, but initial management consists of a low-salt diet and a potassium-sparing diuretic.
Patients with persistent or recurrent vertigo secondary to unilateral vestibular weakness (such as secondary to vestibular neuronitis) usually benefit from vestibular rehabilitation therapy done by an experienced physical therapist. Most patients compensate well, although some, especially older patients, have more difficulty. Physical therapy can also provide important safety information for older patients or particularly disabled patients.
As people age, organs involved in balance function less well. For example, seeing in dim light becomes more difficult, inner ear structures deteriorate, proprioception becomes less sensitive, and mechanisms that control blood pressure become less responsive (eg, to postural changes, postprandial demands). Older people also are more likely to have cardiac or cerebrovascular disorders that can contribute to dizziness. They also are more likely to be taking drugs that can cause dizziness, including those for hypertension, angina, heart failure, seizures, and anxiety, as well as certain antibiotics, antihistamines, and sleep aids. Thus, dizziness in older patients usually has more than one cause.
Although unpleasant at any age, the consequences of dizziness and vertigo are a particular problem for older patients. Patients with frailty are at significant risk of falling with consequent fractures; their fear of moving and falling often significantly decreases their ability to do daily activities.
In addition to treatment of specific causes, older patients with dizziness or vertigo may benefit from physical therapy and exercises to strengthen muscles and help maintain independent ambulation as long as possible.
Vague or inconsistently described symptoms may still be associated with a serious condition.
Cerebrovascular disease and drug effects should be sought, particularly in older patients.
Peripheral vestibular system disorders should be differentiated from central vestibular system disorders.
Immediate neuroimaging should be done when symptoms are accompanied by headache, focal neurologic abnormalities, or both.