Dizziness is an impairment in spatial perception and stability. Because the term dizziness is imprecise, it can refer to vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness.
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.
- 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.
Many conditions are associated with dizziness. 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. The medical conditions that often have dizziness as a symptom include:
- Benign paroxysmal positional vertigo
- Meniere's disease
- Vestibular neuronitis
- Otitis media
- Brain tumor
- Acoustic neuroma
- Motion sickness
- Ramsay Hunt syndrome
- Multiple sclerosis
- low blood pressure (hypotension)
- low blood oxygen content (hypoxemia)
- heart attack
- iron deficiency (anemia)
- low blood sugar (hypoglycemia)
- hormonal changes (e.g. thyroid disease, menstruation, pregnancy)
- panic disorder
- age-diminished visual, balance, and perception of spatial orientation abilities
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.
Common physiological causes of dizziness include:
- inadequate blood supply to the brain due to:
- loss or distortion of vision or visual cues
- disorders of the inner ear
- distortion of brain/nervous function by medications such as anticonvulsants and sedatives
- result of side effect from prescription drugs, including proton-pump inhibitor drugs (PPIs) and Coumadin (warfarin) causing dizziness/fainting 
About 20–30% of the population report to have experienced dizziness at some point in the previous year.
- Balance disorder
- Broken escalator phenomenon
- Coriolis effect (perception)
- Ideomotor phenomenon
- Illusions of self-motion
- Motion sickness
- Postural orthostatic tachycardia syndrome
- Spatial disorientation
- The spins, a state of dizziness and disorientation due to intoxication
- "dizziness" at Dorland's Medical Dictionary
- Dizziness at the US National Library of Medicine Medical Subject Headings (MeSH)
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