Dizziness

Dizziness is an impairment in spatial perception and stability.^[1] Because the term dizziness is imprecise,^[2] it can refer to vertigo, presyncope, disequilibrium,^[3] or a non-specific feeling such as giddiness or foolishness.^[4]

One can induce dizziness by engaging in disorientating activities such as spinning.

• Vertigo is the sensation of spinning or having one's surroundings spin about them. Many people find vertigo very disturbing and often report associated nausea and vomiting. It represents about 25% of cases of occurrences of dizziness.^[5]
• Disequilibrium is the sensation of being off balance, and is most often characterized by frequent falls in a specific direction. This condition is not often associated with nausea or vomiting.
• Presyncope is lightheadedness, muscular weakness and feeling faint as opposed to a syncope, which is actually fainting.
• Non-specific dizziness is often psychiatric in origin. It is a diagnosis of exclusion and can sometimes be brought about by hyperventilation.^[4]

A stroke is the cause of isolated dizziness in 0.7% of people who present to the emergency room.^[5]

Classification

Dizziness is broken down into 4 main subtypes: vertigo (~50%), disequilibrium (less than ~15%), presyncope (less than ~15%) and lightheadedness (~10%).^[6]

Differential diagnosis

Many conditions are associated with dizziness. Dizziness can accompany certain serious events, such as a concussion or brain bleed, epilepsy and seizures (convulsions), strokes, and cases of meningitis and encephalitis. However, the most common subcategories can be broken down as follows: 40% peripheral vestibular dysfunction, 10% central nervous system lesion, 15% psychiatric disorder, 25% presyncope/dysequilibrium, and 10% nonspecific dizziness.^[7] Some vestibular pathologies have symptoms that are comorbid with mental disorders.^[8] The medical conditions that often have dizziness as a symptom include:^{[7][9][10][11]}

• Benign paroxysmal positional vertigo
• Meniere's disease
• Vestibular neuronitis
• Labyrinthitis
• Otitis media
• Brain tumor
• Acoustic neuroma
• Motion sickness
• Ramsay Hunt syndrome
• Migraine
• Multiple sclerosis
• Pregnancy
• low blood pressure (hypotension)
• low blood oxygen content (hypoxemia)
• heart attack^[12]
• iron deficiency (anemia)
• low blood sugar (hypoglycemia)
• hormonal changes (e.g. thyroid disease, menstruation, pregnancy)
• panic disorder
• hyperventilation
• anxiety
• depression
• age-diminished visual, balance, and perception of spatial orientation abilities

Mechanism

Many conditions cause dizziness because multiple parts of the body are required for maintaining balance including the inner ear, eyes, muscles, skeleton, and the nervous system.^[10]

Common physiological causes of dizziness include:

• inadequate blood supply to the brain due to:
  • a sudden fall in blood pressure^[10]
  • heart problems or artery blockages^[10]
• loss or distortion of vision or visual cues^[10]
• disorders of the inner ear^[10]
• distortion of brain/nervous function by medications such as anticonvulsants and sedatives^[10]
• result of side effect from prescription drugs, including proton-pump inhibitor drugs (PPIs)^[13] and Coumadin (warfarin) causing dizziness/fainting ^[14]

Epidemiology

About 20–30% of the population report to have experienced dizziness at some point in the previous year.^[5]

See also

• Balance disorder
• Broken escalator phenomenon
• Coriolis effect (perception)
• Equilibrioception
• Ideomotor phenomenon
• Illusions of self-motion
• Motion sickness
• Postural orthostatic tachycardia syndrome
• Proprioception
• Seasickness
• Spatial disorientation
• The spins, a state of dizziness and disorientation due to intoxication
• Vertigo

References

External links

• Dizzytimes.com Online Community for Sufferers of Vertigo and Dizziness
• Dysautonomia Youth Network of America, Inc.