Definition and Overview
Dizziness is a general term for symptoms in which perception of one's own or the surrounding environment's position and movement is distorted. According to a large-scale German epidemiological survey, approximately 22.9% of adults experienced moderate or greater dizziness in the past year [1].
According to the international vestibular disorder classification criteria, dizziness is divided into the following four types [3].
- Vertigo: A sensation that the surroundings are spinning. Caused by asymmetric signals from the vestibular apparatus.
- Non-rotatory dizziness: A feeling of lightheadedness or unsteadiness. No spinning sensation is present.
- Presyncope: A feeling of impending faint with visual darkening. Caused by reduced cerebral blood flow.
- Disequilibrium: Difficulty maintaining balance while walking. Common in elderly patients.
These four types can overlap, and it is common for a single patient to present with multiple types simultaneously.
Etiology
The causes of dizziness can be broadly divided into peripheral, central, autonomic, and other categories.
Peripheral Causes
Approximately 60-70% of all dizziness patients have peripheral causes [2]. These arise from problems in the vestibular apparatus or vestibular nerve within the inner ear. The most representative conditions are BPPV (benign paroxysmal positional vertigo), vestibular neuritis, and Meniere's disease.
Central Causes
Dizziness occurs when the cerebellum or brainstem is affected by vascular insufficiency, tumors, or demyelinating lesions. Central causes account for approximately 10-15% of all dizziness patients, but differentiation is critical as they include life-threatening conditions such as stroke [4].
Autonomic Causes
Orthostatic hypotension and vasovagal syncope are the most representative autonomic causes. Orthostatic hypotension is diagnosed when systolic blood pressure drops by 20 mmHg or more upon standing [4]. Autonomic nervous system dysfunction impairs blood pressure maintenance, reducing cerebral blood flow and producing presyncope or syncope.
Other Causes
Anemia, hypoglycemia, medication side effects, anxiety disorders, and hyperventilation syndrome can also cause dizziness.
Major Conditions
Benign Paroxysmal Positional Vertigo (BPPV)
Benign paroxysmal positional vertigo (BPPV) is the most common vestibular disorder, accounting for approximately 20-30% of all dizziness patients [2]. Otoliths (calcium carbonate crystals) from the vestibular organ migrate into the semicircular canals, causing rotatory vertigo lasting seconds to one minute triggered by positional changes such as turning the head or lying down. The Epley maneuver (canalith repositioning) resolves symptoms in 80-90% of patients [2].
Meniere's Disease
The underlying cause is endolymphatic hydrops (excess endolymphatic fluid in the inner ear). Recurrent episodes of rotatory vertigo lasting 20 minutes to several hours are accompanied by fluctuating hearing loss, tinnitus, and aural fullness. The prevalence is approximately 50-200 per 100,000 population [1].
Vestibular Neuritis
Vestibular neuritis is a condition in which inflammation of the vestibular nerve causes sudden severe rotatory vertigo persisting for several days. Viral infection is presumed to be the primary cause. The absence of hearing loss is the key differentiating feature from Meniere's disease [3].
Orthostatic Hypotension
Orthostatic hypotension is defined as a decrease in systolic blood pressure of 20 mmHg or more, or diastolic blood pressure of 10 mmHg or more, upon standing from a supine position. The prevalence reaches approximately 15-30% in adults aged 65 and older [4]. Reduced cerebral blood flow causes dizziness, blurred vision, and syncope.
Vasovagal Syncope
Prolonged standing, pain, and emotional stress act as triggers that excessively activate the vagus nerve, causing a sudden drop in blood pressure and heart rate leading to syncope. It is the most common type, accounting for approximately 21-40% of all syncope cases [4].
Psychogenic Dizziness
Persistent postural-perceptual dizziness (PPPD) is the most representative condition. Non-rotatory dizziness persists for more than 3 months even in the absence of organic vestibular disease or after recovery [6]. It is frequently accompanied by anxiety disorders and depression, and vestibular rehabilitation therapy and selective serotonin reuptake inhibitors (SSRIs) are used for treatment.
Warning Signs of Dangerous Dizziness
If the following symptoms are present, central causes such as stroke should be suspected, and emergency medical services should be sought immediately [4][5].
- Sudden severe dizziness persists regardless of posture.
- Weakness or abnormal sensation develops in one side of the body.
- Speech becomes slurred or the patient cannot understand others' speech.
- Seeing double (diplopia).
- Balance is so severely impaired that walking is impossible.
- Severe headache unlike any previously experienced accompanies the dizziness.
The HINTS examination -- which comprehensively evaluates nystagmus pattern, head impulse test, and gaze deviation in patients with acute dizziness -- demonstrates higher sensitivity than MRI for differentiating stroke (approximately 96% or greater within 48 hours of onset) [4].
Diagnosis
Differential diagnosis of dizziness begins with systematic history-taking. Identifying the type of dizziness, duration, triggers, and accompanying symptoms is the most critical step [3].
The major diagnostic tests are as follows.
- Nystagmus test: Observes for abnormal eye movements. Essential for differentiating peripheral from central causes.
- Video head impulse test (vHIT): Evaluates vestibulo-ocular reflex function. Abnormal findings appear in peripheral vestibular disorders.
- Dix-Hallpike test: The standard test for diagnosing BPPV. A positive result is indicated by provocation of rotatory nystagmus in a specific position [2].
- Electronystagmography (ENG): Quantitatively evaluates bilateral asymmetry of vestibular function.
- Tilt table test: Used for diagnosing orthostatic hypotension and vasovagal syncope.
- Audiometry: Necessary for differentiating inner ear disorders such as Meniere's disease.
- Brain MRI: Performed when central causes are suspected.
Lifestyle Guide
Along with treatment of the underlying condition, lifestyle management helps improve symptoms.
- Avoid sudden postural changes. When rising from a supine position, sit on the edge of the bed for at least 30 seconds before standing.
- Maintain adequate fluid intake. Drinking 1.5-2 liters of water per day helps maintain blood volume.
- Regular aerobic exercise is beneficial for vestibular function recovery and autonomic nervous system balance.
- Avoid sleep deprivation and overexertion. Fatigue is a major factor that exacerbates dizziness.
- Reduce excessive caffeine and alcohol intake. These can affect vestibular function and blood pressure regulation.
- If dizziness recurs, record the circumstances, duration, and accompanying symptoms and bring this log to your medical appointment.
If dizziness recurs for more than two weeks or is severe enough to interfere with daily activities, you should see a specialist for differential diagnosis.