Dizziness
Encyclopedia
Dizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean 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.
A stroke
is the cause of isolated dizziness in 0.7% of people who present to the emergency room.
(~50%), disequilibrium
(less than ~15%), presyncope
(less than ~15%) and lightheadedness
(~10%).
Common physiological causes of dizziness include:
Vertigo (medical)
Vertigo is a type of dizziness, where there is a feeling of motion when one is stationary. The symptoms are due to a dysfunction of the vestibular system in the inner ear...
, presyncope
Presyncope
Presyncope is a state consisting of lightheadedness, muscular weakness, and feeling faint . Pre-syncope does not result from primary central nervous system pathology, nor does it originate in the inner ear, but is most often cardiovascular in etiology. In many patients, lightheadedness is a symptom...
, disequilibrium
Disequilibrium
Disequilibrium is a term used to describe the lack of or opposite of an equilibrium.* in medicine:** Disequilibrium in cerebral palsy - a syndrome described by Hagberg & all** lack of equilibrioception...
, or a non-specific feeling such as giddiness or foolishness.
One can induce dizziness by engaging in disorientating activities such as spinning.
- VertigoVertigo (medical)Vertigo is a type of dizziness, where there is a feeling of motion when one is stationary. The symptoms are due to a dysfunction of the vestibular system in the inner ear...
is a specific medical term used to describe 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. - DisequilibriumEquilibrioceptionEquilibrioception or sense of balance is one of the physiological senses. It helps prevent humans and animals from falling over when walking or standing still. Balance is the result of a number of body systems working together: the eyes , ears and the body's sense of where it is in space ideally...
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. - PresyncopePresyncopePresyncope is a state consisting of lightheadedness, muscular weakness, and feeling faint . Pre-syncope does not result from primary central nervous system pathology, nor does it originate in the inner ear, but is most often cardiovascular in etiology. In many patients, lightheadedness is a symptom...
is lightheadednessLightheadednessLight-headedness is a common and often unpleasant sensation of dizziness and/or feeling that one may be about to faint, which may be transient, recurrent, or occasionally chronic. In some cases, the individual may feel as though his or her head is weightless. The individual may also feel as...
, muscular weakness and feeling faint as opposed to a syncopeSyncope (medicine)Syncope , the medical term for fainting, is precisely defined as a transient loss of consciousness and postural tone characterized by rapid onset, short duration, and spontaneous recovery due to global cerebral hypoperfusion that most often results from hypotension.Many forms of syncope are...
, 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.
A stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
is the cause of isolated dizziness in 0.7% of people who present to the emergency room.
Classification
Dizziness is broken down into 4 main subtypes: vertigoVertigo
Vertigo is a form of dizziness.Vertigo may also refer to:* Vertigo , a 1958 film by Alfred Hitchcock**Vertigo , its soundtrack** Vertigo effect, or Dolly zoom, a special effect in film, named after the movie...
(~50%), disequilibrium
Disequilibrium
Disequilibrium is a term used to describe the lack of or opposite of an equilibrium.* in medicine:** Disequilibrium in cerebral palsy - a syndrome described by Hagberg & all** lack of equilibrioception...
(less than ~15%), presyncope
Presyncope
Presyncope is a state consisting of lightheadedness, muscular weakness, and feeling faint . Pre-syncope does not result from primary central nervous system pathology, nor does it originate in the inner ear, but is most often cardiovascular in etiology. In many patients, lightheadedness is a symptom...
(less than ~15%) and lightheadedness
Lightheadedness
Light-headedness is a common and often unpleasant sensation of dizziness and/or feeling that one may be about to faint, which may be transient, recurrent, or occasionally chronic. In some cases, the individual may feel as though his or her head is weightless. The individual may also feel as...
(~10%).
Differential diagnosis
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 vertigoBenign paroxysmal positional vertigoBenign paroxysmal positional vertigo is a disorder caused by problems in the inner ear. Its symptoms are repeated episodes of positional vertigo, that is, of a spinning sensation caused by changes in the position of the head.-Classification:...
- Meniere's diseaseMénière's diseaseMénière's disease is a disorder of the inner ear that can affect hearing and balance to a varying degree. It is characterized by episodes of vertigo and tinnitus and progressive hearing loss, usually in one ear. It is named after the French physician Prosper Ménière, who, in an article published...
- Vestibular neuronitisVestibular neuronitisVestibular neuronitis, also called Vestibular neuritis, can be a paroxysmal, single attack of vertigo, a series of attacks, or a persistent condition which diminishes over three to six weeks. It is a type of unilateral vestibular dysfunction and may be associated with nausea, vomiting, and...
- LabyrinthitisLabyrinthitisLabyrinthitis is an inflammation of the inner ear, and a form of unilateral vestibular dysfunction. It derives its name from the labyrinths that house the vestibular system . Labyrinthitis can cause balance disorders....
- Otitis mediaOtitis mediaOtitis media is inflammation of the middle ear, or a middle ear infection.It occurs in the area between the tympanic membrane and the inner ear, including a duct known as the eustachian tube. It is one of the two categories of ear inflammation that can underlie what is commonly called an earache,...
- Acoustic neuromaAcoustic neuromaA vestibular schwannoma, often called an acoustic neuroma, is a benign primary intracranial tumor of the myelin-forming cells of the vestibulocochlear nerve . The term "vestibular schwannoma" involves the vestibular portion of the 8th cranial nerve and arises from Schwann cells, which are...
- Chronic motion sickness
- Ramsay Hunt syndrome
- MigraineMigraineMigraine is a chronic neurological disorder characterized by moderate to severe headaches, and nausea...
- Multiple sclerosisMultiple sclerosisMultiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms...
- pregnancyPregnancyPregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...
- low blood pressure (hypotensionHypotensionIn physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...
) - low blood oxygen content (hypoxemiaHypoxemiaHypoxemia is generally defined as decreased partial pressure of oxygen in blood, sometimes specifically as less than or causing hemoglobin oxygen saturation of less than 90%.-Distinction from anemia and hypoxia:...
) - iron deficiency (anemiaAnemiaAnemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...
) - low blood sugar (hypoglycemiaHypoglycemiaHypoglycemia or hypoglycæmia is the medical term for a state produced by a lower than normal level of blood glucose. The term literally means "under-sweet blood"...
) - hormonal changes (e.g., thyroid disease, menstruation, pregnancy)
- panic disorderPanic disorderPanic disorder is an anxiety disorder characterized by recurring severe panic attacks. It may also include significant behavioral change lasting at least a month and of ongoing worry about the implications or concern about having other attacks. The latter are called anticipatory attacks...
- hyperventilationHyperventilationHyperventilation or overbreathing is the state of breathing faster or deeper than normal, causing excessive expulsion of circulating carbon dioxide. It can result from a psychological state such as a panic attack, from a physiological condition such as metabolic acidosis, can be brought about by...
- anxietyAnxietyAnxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...
- 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.Common physiological causes of dizziness include:
- inadequate blood supply to the brain due to:
- a sudden fall in blood pressure
- heart problems or artery blockages
- 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
Epidemiology
About 20–30% of the population report to have experienced dizziness at some point in the previous year.See also
- Motion sicknessMotion sicknessMotion sickness or kinetosis, also known as travel sickness, is a condition in which a disagreement exists between visually perceived movement and the vestibular system's sense of movement...
- Balance disorderBalance disorderA balance disorder is a disturbance that causes an individual to feel unsteady, for example when standing or walking. It may be accompanied by feelings of giddiness or wooziness, or having a sensation of movement, spinning, or floating...
- Postural orthostatic tachycardia syndromePostural orthostatic tachycardia syndromePostural orthostatic tachycardia syndrome is a condition of dysautonomia, more specifically orthostatic intolerance, in which a change from the supine position to an upright position causes an abnormally large increase in heart rate, called tachycardia...
- EquilibrioceptionEquilibrioceptionEquilibrioception or sense of balance is one of the physiological senses. It helps prevent humans and animals from falling over when walking or standing still. Balance is the result of a number of body systems working together: the eyes , ears and the body's sense of where it is in space ideally...
- The spinsThe spinsThe spins is a term used to describe an adverse reaction of intoxication that causes a state of vertigo and nausea, causing one to feel as if he or she is "spinning out of control". It is most commonly associated with drunkenness or mixing alcohol with other psychoactive drugs such as cannabis...
, a state of dizziness and disorientation due to intoxication - Coriolis effect (perception)Coriolis effect (perception)In psychophysical perception, the Coriolis effect is the misperception of body orientation and induced nausea due to the Coriolis force ....
External links
- Dizzytimes.com Online Community for Sufferers of Vertigo and Dizziness
- Dysautonomia Youth Network of America, Inc.