Dizziness is an imprecise term that can refer to a sense of disorientation in space,

vertigo Vertigo is a condition where a person has the sensation of movement or of surrounding objects moving when they are not. Often it feels like a spinning or swaying movement. This may be associated with nausea, vomiting, sweating, or difficulties w ...

, or

lightheadedness Lightheadedness is a common and typically unpleasant sensation of dizziness or a feeling that one may faint. The sensation of lightheadedness can be short-lived, prolonged, or, rarely, recurring. In addition to dizziness, the individual may feel ...

. It can also refer to disequilibrium or a non-specific feeling, such as giddiness or

foolishness Foolishness is the unawareness or lack of social norms which causes offence, annoyance, trouble and/or injury. The things such as impulsivity and/or influences may affect a person's ability to make otherwise reasonable decisions. In this ...

. Dizziness is a common medical complaint, affecting 20-30% of persons. Dizziness is broken down into 4 main subtypes:

(~25-50%), disequilibrium (less than ~15%),

presyncope Lightheadedness is a common and typically unpleasant sensation of dizziness or a feeling that one may faint. The sensation of lightheadedness can be short-lived, prolonged, or, rarely, recurring. In addition to dizziness, the individual may feel ...

(less than ~15%), and nonspecific dizziness (~10%). *

Vertigo Vertigo is a condition where a person has the sensation of movement or of surrounding objects moving when they are not. Often it feels like a spinning or swaying movement. This may be associated with nausea, vomiting, sweating, or difficulties w ...

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. *

Presyncope Lightheadedness is a common and typically unpleasant sensation of dizziness or a feeling that one may faint. The sensation of lightheadedness can be short-lived, prolonged, or, rarely, recurring. In addition to dizziness, the individual may feel ...

describes

or feeling faint; the name relates to syncope, which is actually fainting. * 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. * Non-specific dizziness may be psychiatric in origin. It is a diagnosis of exclusion and can sometimes be brought about by hyperventilation.

Mechanism and causes

Many conditions cause dizziness because multiple parts of the body are required for maintaining balance including the inner ear,

eyes Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and con ...

, muscles, skeleton, and the

nervous system In biology, the nervous system is the highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes ...

. Thus dizziness can be caused by a variety of problems and may reflect a focal process (such as one affecting balance or coordination) or a diffuse one (such as a toxic exposure or low perfusion state). Common causes of dizziness include: * Inadequate blood supply to the

brain A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a ve ...

due to: ** A sudden fall in blood pressure **

Heart problems Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, ...

or artery blockages **

Anaemia Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, t ...

s, such as

Vitamin B12 deficiency anemia Pernicious anemia is a type of vitamin B12 deficiency anemia, a disease in which not enough red blood cells are produced due to the malabsorption of vitamin B12. Malabsorption in pernicious anemia results from the lack or loss of intrinsic fa ...

, Iron deficiency anemia * Visual impairment, Loss or distortion of vision or sensory cue, visual cues * Standing too quickly/prolonged standing * Disorders of the inner ear * Dehydration * Distortion of brain/nervous function by medications such as anticonvulsants and sedatives * Dysfunction of cervical proprioception * Side effects from other prescription drugs, such as proton-pump inhibitors or Coumadin (warfarin)

Diagnosis

Differential diagnosis

Dizziness may occur from an abnormality involving the brain (in particular the brainstem or cerebellum), inner ear, eyes, heart, vascular system, fluid or blood volume, spinal cord, peripheral nerves, or body electrolytes. 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/disequilibrium, and 10% nonspecific dizziness. Some vestibular pathologies have symptoms that are comorbid with mental disorders. While traditional medical teaching has focused on determining the cause of dizziness based on the category (e.g. vertigo vs presyncope), recent research suggests that this analysis is of limited clinical utility. Medical conditions that often have dizziness as a symptom include: * Benign paroxysmal positional vertigo * Ménière's disease * 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 * Iron deficiency (anemia) * Vitamin B12 deficiency * Low blood sugar (hypoglycemia) * Hormonal changes (e.g. thyroid disease, menstruation, pregnancy) * Panic disorder * Hyperventilation * Anxiety * Major depressive disorder, Depression * Age-diminished visual, balance, and perception of spatial orientation abilities * a stroke is the cause of isolated dizziness in 0.7% of people who present to the emergency department.

Epidemiology

About 20–30% of the population report to have experienced dizziness at some point in 2008.

Disequilibrium

In medicine, disequilibrium refers to impaired equilibrioception that can be characterised as a sensation of impending fall or of the need to obtain external assistance for proper locomotion. It is sometimes described as a feeling of improper tilt of the floor, or as a sense of floating. This sensation can originate in the inner ear or other motion sensors, or in the central nervous system. Neurologic disorders tend to cause constant vertigo or disequilibrium and usually have other symptoms of neurologic dysfunction associated with the vertigo. Many medications used to treat seizures, depression, anxiety, and pain affect the vestibular system and the central nervous system which can cause the symptom of disequilibrium.

References

External links

Dizzytimes.com
Online Community for People with Vertigo and Dizziness
Dysautonomia Youth Network of America, Inc.
{{Authority control Neurological disorders