Dizziness is an imprecise term that can refer to a sense of disorientation in space,
vertigo, or
lightheadedness. It can also refer to
disequilibrium or a non-specific feeling, such as giddiness or
foolishness.
Dizziness is a common medical complaint, affecting 20-30% of persons. Dizziness is broken down into 4 main subtypes:
vertigo (~25-50%),
disequilibrium (less than ~15%),
presyncope (less than ~15%), and nonspecific dizziness (~10%).
*
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.
[
* Presyncope describes lightheadedness 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
Hyperventilation is irregular breathing that occurs when the rate or tidal volume of breathing eliminates more carbon dioxide than the body can produce. This leads to hypocapnia, a reduced concentration of carbon dioxide dissolved in the blood. ...
.[
]
Mechanism and causes
Many conditions cause dizziness because multiple parts of the body are required for maintaining balance including the inner ear
The inner ear (internal ear, auris interna) is the innermost part of the vertebrate ear. In vertebrates, the inner ear is mainly responsible for sound detection and balance. In mammals, it consists of the bony labyrinth, a hollow cavity in the ...
, eyes, muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...
s, skeleton
A skeleton is the structural frame that supports the body of an animal. There are several types of skeletons, including the exoskeleton, which is the stable outer shell of an organism, the endoskeleton, which forms the support structure inside ...
, 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 th ...
. Thus dizziness can be caused by a variety of problems and may reflect a focal process (such as one affecting balance or coordination
Coordination may refer to:
* Coordination (linguistics), a compound grammatical construction
* Coordination complex, consisting of a central atom or ion and a surrounding array of bound molecules or ions
* Coordination number or ligancy of a centr ...
) or a diffuse one (such as a toxic exposure or low perfusion
Perfusion is the passage of fluid through the circulatory system or lymphatic system to an organ or a tissue, usually referring to the delivery of blood to a capillary bed in tissue. Perfusion is measured as the rate at which blood is deliver ...
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 v ...
due to:
** A sudden fall in blood pressure
Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressure" r ...
** 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, th ...
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
Iron-deficiency anemia is anemia caused by a lack of iron. Anemia is defined as a decrease in the number of red blood cells or the amount of hemoglobin in the blood. When onset is slow, symptoms are often vague such as feeling tired, weak, shor ...
* Loss or distortion of vision or visual cues
The visual system comprises the sensory organ (the eye) and parts of the central nervous system (the retina containing photoreceptor cells, the optic nerve, the optic tract and the visual cortex) which gives organisms the sense of sight (th ...
* Standing too quickly/prolonged standing
* Disorders of the inner ear
* Dehydration
In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mil ...
* Distortion of brain/nervous function by medications such as anticonvulsant
Anticonvulsants (also known as antiepileptic drugs or recently as antiseizure drugs) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of b ...
s and sedative
A sedative or tranquilliser is a substance that induces sedation by reducing irritability or excitement. They are CNS depressants and interact with brain activity causing its deceleration. Various kinds of sedatives can be distinguished, but t ...
s
* Dysfunction of cervical proprioception
* Side effects from other prescription drugs, such as proton-pump inhibitors or Coumadin (warfarin
Warfarin, sold under the brand name Coumadin among others, is a medication that is used as an anticoagulant (blood thinner). It is commonly used to prevent blood clots such as deep vein thrombosis and pulmonary embolism, and to prevent strok ...
)
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
Labyrinthitis is inflammation of the labyrinth – a maze of fluid-filled channels in the inner ear. Vestibular neuritis is inflammation of the vestibular nerve – the nerve in the inner ear that sends messages related to motion and position t ...
* Otitis media
Otitis media is a group of inflammatory diseases of the middle ear. One of the two main types is acute otitis media (AOM), an infection of rapid onset that usually presents with ear pain. In young children this may result in pulling at the ear, ...
* Brain tumor
A brain tumor occurs when abnormal cells form within the brain. There are two main types of tumors: malignant tumors and benign (non-cancerous) tumors. These can be further classified as primary tumors, which start within the brain, and seconda ...
* Acoustic neuroma
* Motion sickness
* Ramsay Hunt syndrome
* Migraine
Migraine (, ) is a common neurological disorder characterized by recurrent headaches. Typically, the associated headache affects one side of the head, is pulsating in nature, may be moderate to severe in intensity, and could last from a few hou ...
* Multiple sclerosis
Multiple (cerebral) sclerosis (MS), also known as encephalomyelitis disseminata or disseminated sclerosis, is the most common demyelinating disease, in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This d ...
* Pregnancy
Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins.
Pregnancy usually occurs by sexual intercourse, but ca ...
* Low blood pressure (hypotension
Hypotension is low blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood. Blood pressure is indicated by two numbers, the systolic blood pressure (the top number) and the dias ...
)
* Low blood oxygen content ( hypoxemia)
* Heart attack
A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which may tr ...
* Iron deficiency (anemia
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, th ...
)
* Vitamin B12 deficiency
Vitamin B12 deficiency, also known as cobalamin deficiency, is the medical condition in which the blood and tissue have a lower than normal level of vitamin B12. Symptoms can vary from none to severe. Mild deficiency may have few or absent symp ...
* Low blood sugar (hypoglycemia
Hypoglycemia, also called low blood sugar, is a fall in blood sugar to levels below normal, typically below 70 mg/dL (3.9 mmol/L). Whipple's triad is used to properly identify hypoglycemic episodes. It is defined as blood glucose belo ...
)
* Hormonal changes (e.g. thyroid disease, menstruation, pregnancy)
* Panic disorder
* Hyperventilation
Hyperventilation is irregular breathing that occurs when the rate or tidal volume of breathing eliminates more carbon dioxide than the body can produce. This leads to hypocapnia, a reduced concentration of carbon dioxide dissolved in the blood. ...
* Anxiety
Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different than fear in that the former is defined as the anticipation of a future threat wh ...
* Depression
* Age-diminished visual, balance, and perception of spatial orientation abilities
* a stroke
A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...
is the cause of isolated dizziness in 0.7% of people who present to the emergency department
An emergency department (ED), also known as an accident and emergency department (A&E), emergency room (ER), emergency ward (EW) or casualty department, is a medical treatment facility specializing in emergency medicine, the acute care of pati ...
.[
]
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.
See also
* Balance disorder
* Broken escalator phenomenon
The broken escalator phenomenon, also known as the escalator effect and the Walker effect, is the sensation of losing balance, confusion or dizziness reported by some people when stepping onto an escalator which is not working. It is said that ther ...
* Chronic subjective dizziness
The term chronic subjective dizziness (CSD) is used to describe a commonly encountered type of dizziness that is not easily categorized into one of several other types, and for which the physical examination is typically normal. Patients with CSD ...
* Coriolis effect (perception)
In psychophysical perception, the Coriolis effect (also referred to as the Coriolis illusion) is the misperception of body orientation and induced nausea due to the Coriolis force. This effect comes about as the head is moved in contrary or simi ...
* Equilibrioception
* Ideomotor phenomenon
The ideomotor phenomenon is a psychological phenomenon wherein a subject makes motions unconsciously. Also called ideomotor response (or ideomotor reflex) and abbreviated to IMR, it is a concept in hypnosis and psychological research. It is deri ...
* Illusions of self-motion
Illusions of self-motion (or "vection") occur when one perceives bodily motion despite no movement taking place. One can experience illusory movements of the whole body or of individual body parts, such as arms or legs.
Vestibular illusions
The v ...
* Motion sickness
* Postural orthostatic tachycardia syndrome
* Proprioception
* Seasickness
Motion sickness occurs due to a difference between actual and expected motion. Symptoms commonly include nausea, vomiting, cold sweat, headache, dizziness, tiredness, loss of appetite, and increased salivation. Complications may rarely include de ...
* Spatial disorientation
Spatial disorientation results in a person being unable to determine their position or relative motion, commonly occurring during periods of challenging visibility, since vision is the dominant sense for orientation. The auditory system, vestibular ...
* The spins
The spins (as in having "the spins")Diane Marie Leiva. ''The Florida State University College of Education''Women's Voices on College Drinking: The First-Year College Experience"/ref> is an adverse reaction of intoxication that causes a state of ve ...
, a state of dizziness and disorientation due to intoxication
* Vertigo
References
External links
Dizzytimes.com
Online Community for People with Vertigo and Dizziness
Dysautonomia Youth Network of America, Inc.
{{Authority control
Neurological disorders