Fatigue (physical)
Encyclopedia
Fatigue is a state of awareness describing a range of afflictions, usually associated with physical and/or mental weakness, though varying from a general state of lethargy to a specific work-induced burning sensation within one's muscles. Physical fatigue is the inability to continue functioning at the level of one's normal abilities. It is widespread in everyday life, but usually becomes particularly noticeable during heavy exercise
. Mental fatigue, on the other hand, rather manifests in somnolence
(sleepiness).
Fatigue is considered a symptom
, as opposed to a medical sign
, because it is reported by the patient instead of being observed by others. Fatigue and ‘feelings of fatigue’ are often confused.
s to the degree that would be expected given the individual's general physical fitness
.
A test of strength is often used during a diagnosis
of a muscular disorder before the etiology
can be identified. Such etiology depends on the type of muscle weakness, which can be true or perceived as well as central or peripheral. True weakness is substantial, while perceived rather is a sensation of having to put more effort to do the same task. On the other hand, central muscle weakness is an overall exhaustion of the whole body, while peripheral weakness is an exhaustion of individual muscles.
(decreased wakefulness), or just as a general decrease of attention
, not necessarily including sleepiness. Decreased attention is known as ego depletion
and occurs when the limited 'self regulatory capacity' is depleted . It may also be described as a more or less decreased level of consciousness. In any case, this can be dangerous when performing tasks that require constant concentration, such as driving a vehicle
. For instance, a person who is sufficiently somnolent may experience microsleep
. However, objective cognitive testing should be done to differentiate the neurocognitive deficits of brain disease from those attributable to tiredness.
, overstimulation and understimulation, jet lag
or active recreation
, depression
, and also boredom
, disease
and lack of sleep
. It may also have chemical causes, such as poison
ing or mineral
or vitamin
deficiencies. Massive blood loss frequently results in fatigue. Fatigue is different from drowsiness, where a patient feels that sleep is required. Fatigue is a normal response to physical exertion or stress, but can also be a sign of a physical disorder.
Temporary fatigue is likely to be a minor illness
like the common cold
as one part of the sickness behavior
response that happens when the immune system
fights an infection
.
Fatigue may also be a side effect of certain medications, e.g. lithium salts, ciprofloxacin
; beta blocker
s, which can induce exercise intolerance
; and many cancer treatments, particularly chemotherapy
and radiotherapy.
If a person with fatigue decides to seek medical advice, the overall goal is to identify and rule out any treatable conditions. This is done by considering the person's medical history
, any other symptoms that are present, and evaluating of the qualities of the fatigue itself. The affected person may be able to identify patterns to the fatigue, such as being more tired at certain times of day, whether fatigue increases throughout the day, and whether fatigue is reduced after taking a nap.
Because disrupted sleep
is a significant contributor to fatigue, a diagnostic evaluation considers the quality of sleep, the emotion
al state of the person, sleep pattern, and stress level. The amount of sleep, the hours that are set aside for sleep, and the number of times that a person awakens during the night are important. A sleep study may be ordered to rule out a sleep disorder
.
Depression and other psychological conditions can produce fatigue, so people who report fatigue are routinely screened for these conditions, along with drug abuse
, poor diet, and lack of physical exercise
, which paradoxically increases fatigue.
Basic medical test
s may be performed to rule out common causes of fatigue. These include blood test
s to check for infection or anemia
, a urinalysis
to look for signs of liver disease
or diabetes mellitus
, and other tests to check for kidney and liver function, such as a comprehensive metabolic panel
. Other tests may be chosen depending on the patient's social history, such as an HIV test
or pregnancy test
.
of the lower brain. Musculoskeletal
structures may have co-evolved with appropriate brain structures so that the complete unit functions together in a constructive and adaptive fashion. The entire systems of muscles, joints, and proprioceptive
and kinesthetic functions plus parts of the brain evolve and function together in a unitary way.
Physical exercise
Physical exercise is any bodily activity that enhances or maintains physical fitness and overall health and wellness. It is performed for various reasons including strengthening muscles and the cardiovascular system, honing athletic skills, weight loss or maintenance, as well as for the purpose of...
. Mental fatigue, on the other hand, rather manifests in somnolence
Somnolence
Somnolence is a state of near-sleep, a strong desire for sleep, or sleeping for unusually long periods . It has two distinct meanings, referring both to the usual state preceding falling asleep, and the chronic condition referring to being in that state independent of a circadian rhythm...
(sleepiness).
Fatigue is considered a symptom
Symptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...
, as opposed to a medical sign
Medical sign
A medical sign is an objective indication of some medical fact or characteristic that may be detected by a physician during a physical examination of a patient....
, because it is reported by the patient instead of being observed by others. Fatigue and ‘feelings of fatigue’ are often confused.
Physical fatigue
Physical fatigue or muscle weakness and/or aches, (or "lack of strength") is a direct term for the inability to exert force with one's muscleMuscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
s to the degree that would be expected given the individual's general physical fitness
Physical fitness
Physical fitness comprises two related concepts: general fitness , and specific fitness...
.
A test of strength is often used during a diagnosis
Medical diagnosis
Medical diagnosis refers both to the process of attempting to determine or identify a possible disease or disorder , and to the opinion reached by this process...
of a muscular disorder before the etiology
Etiology
Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....
can be identified. Such etiology depends on the type of muscle weakness, which can be true or perceived as well as central or peripheral. True weakness is substantial, while perceived rather is a sensation of having to put more effort to do the same task. On the other hand, central muscle weakness is an overall exhaustion of the whole body, while peripheral weakness is an exhaustion of individual muscles.
Mental fatigue
In addition to physical, fatigue also includes mental fatigue, not necessarily including any muscle fatigue. Such a mental fatigue, in turn, can manifest itself both as somnolenceSomnolence
Somnolence is a state of near-sleep, a strong desire for sleep, or sleeping for unusually long periods . It has two distinct meanings, referring both to the usual state preceding falling asleep, and the chronic condition referring to being in that state independent of a circadian rhythm...
(decreased wakefulness), or just as a general decrease of attention
Attention
Attention is the cognitive process of paying attention to one aspect of the environment while ignoring others. Attention is one of the most intensely studied topics within psychology and cognitive neuroscience....
, not necessarily including sleepiness. Decreased attention is known as ego depletion
Ego depletion
Ego depletion refers to the idea that self-control or willpower is an exhaustible resource that can be used up. When that energy is low, mental activity that requires self-control is impaired. In other words, using one's self-control impairs the ability to control one's self later on. In this...
and occurs when the limited 'self regulatory capacity' is depleted . It may also be described as a more or less decreased level of consciousness. In any case, this can be dangerous when performing tasks that require constant concentration, such as driving a vehicle
Vehicle
A vehicle is a device that is designed or used to transport people or cargo. Most often vehicles are manufactured, such as bicycles, cars, motorcycles, trains, ships, boats, and aircraft....
. For instance, a person who is sufficiently somnolent may experience microsleep
Microsleep
A microsleep is an episode of sleep which may last for a fraction of a second or up to thirty seconds. Often, it is the result of sleep deprivation, mental fatigue, depression, sleep apnea, hypoxia, narcolepsy, or hypersomnia...
. However, objective cognitive testing should be done to differentiate the neurocognitive deficits of brain disease from those attributable to tiredness.
Causes
Fatigue is a normal result of working, mental stressStress (medicine)
Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...
, overstimulation and understimulation, jet lag
Jet lag
Jet lag, medically referred to as desynchronosis, is a physiological condition which results from alterations to the body's circadian rhythms; it is classified as one of the circadian rhythm sleep disorders...
or active recreation
Recreation
Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or pleasure and are considered to be "fun"...
, depression
Clinical depression
Major depressive disorder is a mental disorder characterized by an all-encompassing low mood accompanied by low self-esteem, and by loss of interest or pleasure in normally enjoyable activities...
, and also boredom
Boredom
Boredom is an emotional state experienced when an individual is without any activity or is not interested in their surroundings. The first recorded use of the word boredom is in the novel Bleak House by Charles Dickens, written in 1852, in which it appears six times, although the expression to be a...
, disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
and lack of sleep
Sleep deprivation
Sleep deprivation is the condition of not having enough sleep; it can be either chronic or acute. A chronic sleep-restricted state can cause fatigue, daytime sleepiness, clumsiness and weight loss or weight gain. It adversely affects the brain and cognitive function. Few studies have compared the...
. It may also have chemical causes, such as poison
Poison
In the context of biology, poisons are substances that can cause disturbances to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism....
ing or mineral
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
or vitamin
Vitamin
A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. In other words, an organic chemical compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on...
deficiencies. Massive blood loss frequently results in fatigue. Fatigue is different from drowsiness, where a patient feels that sleep is required. Fatigue is a normal response to physical exertion or stress, but can also be a sign of a physical disorder.
Temporary fatigue is likely to be a minor illness
Illness
Illness is a state of poor health. Illness is sometimes considered another word for disease. Others maintain that fine distinctions exist...
like the common cold
Common cold
The common cold is a viral infectious disease of the upper respiratory system, caused primarily by rhinoviruses and coronaviruses. Common symptoms include a cough, sore throat, runny nose, and fever...
as one part of the sickness behavior
Sickness behavior
thumb|350px|right|[[Michael Peter Ancher|Ancher, Michael]], "The Sick Girl", 1882, [[Statens Museum for Kunst]]Sickness behavior is a coordinated set of adaptive behavioral changes that develop in ill individuals during the course of an infection....
response that happens when the immune system
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
fights an infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
.
Chronic fatigue
Prolonged fatigue is a self-reported, persistent (constant) fatigue lasting at least one month. Chronic fatigue is a self-reported fatigue lasting at least six consecutive months. Chronic fatigue may be either persistent or relapsing. Chronic fatigue is a symptom of a large number of different diseases or conditions. Some major categories of diseases that feature fatigue include:- Autoimmune diseaseAutoimmune diseaseAutoimmune diseases arise from an overactive immune response of the body against substances and tissues normally present in the body. In other words, the body actually attacks its own cells. The immune system mistakes some part of the body as a pathogen and attacks it. This may be restricted to...
s such as celiac disease, 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...
, and spondyloarthropathySpondyloarthropathySpondyloarthropathy is any joint disease of the vertebral column. Spondyloarthropathy with inflammation is called spondylarthritis. In contrast, spondylopathy is a disease of the vertebra itself, but many conditions involve both spondylopathy and spondyloarthropathy... - Blood disorders such as 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...
and hemochromatosis - CancerCancerCancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
- Chronic fatigue syndromeChronic fatigue syndromeChronic fatigue syndrome is the most common name used to designate a significantly debilitating medical disorder or group of disorders generally defined by persistent fatigue accompanied by other specific symptoms for a minimum of six months, not due to ongoing exertion, not substantially...
(CFS) - Drug abuseDrug abuseSubstance abuse, also known as drug abuse, refers to a maladaptive pattern of use of a substance that is not considered dependent. The term "drug abuse" does not exclude dependency, but is otherwise used in a similar manner in nonmedical contexts...
- Depression and other mental disorders that feature depressed moodDepression (mood)Depression is a state of low mood and aversion to activity that can affect a person's thoughts, behaviour, feelings and physical well-being. Depressed people may feel sad, anxious, empty, hopeless, helpless, worthless, guilty, irritable, or restless...
- Eating disorders, which can produce fatigue due to inadequate nutrition
- Endocrine diseaseEndocrine diseaseEndocrine diseases are disorders of the endocrine system. The branch of medicine associated with endocrine disorders is known as endocrinology.-Types of endocrine disease:Broadly speaking, endocrine disorders may be subdivided into three groups:...
s like diabetes mellitusDiabetes mellitusDiabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...
and hypothyroidismHypothyroidismHypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone.Iodine deficiency is the most common cause of hypothyroidism worldwide but it can be caused by other causes such as several conditions of the thyroid gland or, less commonly, the pituitary gland or... - FibromyalgiaFibromyalgiaFibromyalgia is a medical disorder characterized by chronic widespread pain and allodynia, a heightened and painful response to pressure. It is an example of a diagnosis of exclusion...
- Heart diseaseHeart diseaseHeart disease, cardiac disease or cardiopathy is an umbrella term for a variety of diseases affecting the heart. , it is the leading cause of death in the United States, England, Canada and Wales, accounting for 25.4% of the total deaths in the United States.-Types:-Coronary heart disease:Coronary...
- Irritable Bowel SyndromeIrritable bowel syndromeIrritable bowel syndrome is a diagnosis of exclusion. It is a functional bowel disorder characterized by chronic abdominal pain, discomfort, bloating, and alteration of bowel habits in the absence of any detectable organic cause. In some cases, the symptoms are relieved by bowel movements...
- Inborn errors of metabolism such as Fructose malabsorptionFructose malabsorptionFructose malabsorption, formerly named "dietary fructose intolerance," is a digestive disorder in which absorption of fructose is impaired by deficient fructose carriers in the small intestine's enterocytes. This results in an increased concentration of fructose in the entire intestine.Fructose...
. - Liver failureLiver failureAcute liver failure is the appearance of severe complications rapidly after the first signs of liver disease , and indicates that the liver has sustained severe damage . The complications are hepatic encephalopathy and impaired protein synthesis...
- Infectious diseases such as infectious mononucleosisInfectious mononucleosisInfectious mononucleosis is an infectious, widespread viral...
. - LeukemiaLeukemiaLeukemia or leukaemia is a type of cancer of the blood or bone marrow characterized by an abnormal increase of immature white blood cells called "blasts". Leukemia is a broad term covering a spectrum of diseases...
or lymphomaLymphomaLymphoma is a cancer in the lymphatic cells of the immune system. Typically, lymphomas present as a solid tumor of lymphoid cells. Treatment might involve chemotherapy and in some cases radiotherapy and/or bone marrow transplantation, and can be curable depending on the histology, type, and stage... - Lyme diseaseLyme diseaseLyme disease, or Lyme borreliosis, is an emerging infectious disease caused by at least three species of bacteria belonging to the genus Borrelia. Borrelia burgdorferi sensu stricto is the main cause of Lyme disease in the United States, whereas Borrelia afzelii and Borrelia garinii cause most...
- Neurological disorderNeurological disorderA neurological disorder is a disorder of the body's nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord, or in the nerves leading to or from them, can result in symptoms such as paralysis, muscle weakness, poor coordination, loss of sensation, seizures,...
s such as narcolepsyNarcolepsyNarcolepsy is a chronic sleep disorder, or dyssomnia, characterized by excessive sleepiness and sleep attacks at inappropriate times, such as while at work. People with narcolepsy often experience disturbed nocturnal sleep and an abnormal daytime sleep pattern, which often is confused with insomnia...
, Parkinson's diseaseParkinson's diseaseParkinson's disease is a degenerative disorder of the central nervous system...
and post-concussion syndromePost-concussion syndromePost-concussion syndrome, also known as postconcussive syndrome or PCS, and historically called shell shock, is a set of symptoms that a person may experience for weeks, months, or occasionally up to a year or more after a concussion – a mild form of traumatic brain injury . PCS may also... - Physical traumaPhysical traumaTrauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...
and other painPainPain is an unpleasant sensation often caused by intense or damaging stimuli such as stubbing a toe, burning a finger, putting iodine on a cut, and bumping the "funny bone."...
-causing conditions, such as arthritisArthritisArthritis is a form of joint disorder that involves inflammation of one or more joints.... - Sleep deprivationSleep deprivationSleep deprivation is the condition of not having enough sleep; it can be either chronic or acute. A chronic sleep-restricted state can cause fatigue, daytime sleepiness, clumsiness and weight loss or weight gain. It adversely affects the brain and cognitive function. Few studies have compared the...
or sleep disorders - UremiaUremiaUremia or uraemia is a term used to loosely describe the illness accompanying kidney failure , in particular the nitrogenous waste products associated with the failure of this organ....
Fatigue may also be a side effect of certain medications, e.g. lithium salts, ciprofloxacin
Ciprofloxacin
Ciprofloxacin is a synthetic chemotherapeutic antibiotic of the fluoroquinolone drug class.It is a second-generation fluoroquinolone antibacterial. It kills bacteria by interfering with the enzymes that cause DNA to rewind after being copied, which stops synthesis of DNA and of...
; beta blocker
Beta blocker
Beta blockers or beta-adrenergic blocking agents, beta-adrenergic antagonists, beta-adrenoreceptor antagonists or beta antagonists, are a class of drugs used for various indications. They are particularly for the management of cardiac arrhythmias, cardioprotection after myocardial infarction ,...
s, which can induce exercise intolerance
Exercise intolerance
Exercise intolerance is a condition where the patient is unable to do physical exercise at the level or for the duration that would be expected of someone in his or her general physical condition, or experiences unusually severe post-exercise pain, fatigue, or other negative effects...
; and many cancer treatments, particularly chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....
and radiotherapy.
Diagnosis
The majority of people who have fatigue do not have an underlying cause discovered after a year with the condition. In those people who have a possible diagnosis, musculoskeletal (19.4%) and psychological problems (16.5%) are the most common. Definitive physical conditions were only found in 8.2%.If a person with fatigue decides to seek medical advice, the overall goal is to identify and rule out any treatable conditions. This is done by considering the person's medical history
Medical history
The medical history or anamnesis of a patient is information gained by a physician by asking specific questions, either of the patient or of other people who know the person and can give suitable information , with the aim of obtaining information useful in formulating a diagnosis and providing...
, any other symptoms that are present, and evaluating of the qualities of the fatigue itself. The affected person may be able to identify patterns to the fatigue, such as being more tired at certain times of day, whether fatigue increases throughout the day, and whether fatigue is reduced after taking a nap.
Because disrupted sleep
Sleep
Sleep is a naturally recurring state characterized by reduced or absent consciousness, relatively suspended sensory activity, and inactivity of nearly all voluntary muscles. It is distinguished from quiet wakefulness by a decreased ability to react to stimuli, and is more easily reversible than...
is a significant contributor to fatigue, a diagnostic evaluation considers the quality of sleep, the emotion
Emotion
Emotion is a complex psychophysiological experience of an individual's state of mind as interacting with biochemical and environmental influences. In humans, emotion fundamentally involves "physiological arousal, expressive behaviors, and conscious experience." Emotion is associated with mood,...
al state of the person, sleep pattern, and stress level. The amount of sleep, the hours that are set aside for sleep, and the number of times that a person awakens during the night are important. A sleep study may be ordered to rule out a sleep disorder
Sleep disorder
A sleep disorder, or somnipathy, is a medical disorder of the sleep patterns of a person or animal. Some sleep disorders are serious enough to interfere with normal physical, mental and emotional functioning...
.
Depression and other psychological conditions can produce fatigue, so people who report fatigue are routinely screened for these conditions, along with drug abuse
Drug abuse
Substance abuse, also known as drug abuse, refers to a maladaptive pattern of use of a substance that is not considered dependent. The term "drug abuse" does not exclude dependency, but is otherwise used in a similar manner in nonmedical contexts...
, poor diet, and lack of physical exercise
Physical exercise
Physical exercise is any bodily activity that enhances or maintains physical fitness and overall health and wellness. It is performed for various reasons including strengthening muscles and the cardiovascular system, honing athletic skills, weight loss or maintenance, as well as for the purpose of...
, which paradoxically increases fatigue.
Basic medical test
Medical test
A diagnostic test is any kind of medical test performed to aid in the diagnosis or detection of disease. For example:* to diagnose diseases, and preferably sub-classify it regarding, for example, severity and treatability...
s may be performed to rule out common causes of fatigue. These include blood test
Blood test
A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a needle, or via fingerprick....
s to check for infection or anemia
Anemia
Anemia 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...
, a urinalysis
Urinalysis
A urinalysis , also known as Routine and Microscopy , is an array of tests performed on urine, and one of the most common methods of medical diagnosis...
to look for signs of liver disease
Liver disease
Liver disease is a broad term describing any single number of diseases affecting the liver.-Diseases:* Hepatitis, inflammation of the liver, caused mainly by various viruses but also by some poisons , autoimmunity or hereditary conditions...
or diabetes mellitus
Diabetes mellitus
Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...
, and other tests to check for kidney and liver function, such as a comprehensive metabolic panel
Comprehensive metabolic panel
The comprehensive metabolic panel, or chemical screen, is a panel of 14 blood tests which serves as an initial broad screening tool for physicians, nurse practitioners and physician assistants...
. Other tests may be chosen depending on the patient's social history, such as an HIV test
HIV test
HIV tests are used to detect the presence of the human immunodeficiency virus , the virus that causes acquired immunodeficiency syndrome , in serum, saliva, or urine. Such tests may detect antibodies, antigens, or RNA.- Terminology :...
or pregnancy test
Pregnancy test
A pregnancy test attempts to determine whether or not a woman is pregnant.These markers are found in urine and blood, and pregnancy tests require sampling one of these substances. The first of these markers to be discovered, human chorionic gonadotropin , was discovered in 1930 to be produced by...
.
Perception of fatigue
The sense of fatigue is believed to originate in the reticular activating systemReticular activating system
The reticular activating system is an area of the brain responsible for regulating arousal and sleep-wake transitions.- History and Etymology :...
of the lower brain. Musculoskeletal
Musculoskeletal system
A musculoskeletal system is an organ system that gives animals the ability to move using the muscular and skeletal systems...
structures may have co-evolved with appropriate brain structures so that the complete unit functions together in a constructive and adaptive fashion. The entire systems of muscles, joints, and proprioceptive
Proprioception
Proprioception , from Latin proprius, meaning "one's own" and perception, is the sense of the relative position of neighbouring parts of the body and strength of effort being employed in movement...
and kinesthetic functions plus parts of the brain evolve and function together in a unitary way.
See also
- Cancer-related fatigueCancer-related fatigueCancer-related fatigue is a subjective symptom of fatigue that is experienced by nearly all cancer patients.Among patients receiving cancer treatment other than surgery, it is essentially universal. Fatigue is a normal and expected side effect from most forms of chemotherapy, radiation therapy,...
- Combat stress reactionCombat stress reactionCombat stress reaction , in the past commonly known as shell shock or battle fatigue, is a range of behaviours resulting from the stress of battle which decrease the combatant's fighting efficiency. The most common symptoms are fatigue, slower reaction times, indecision, disconnection from one's...
- Fatigue (safety)Fatigue (safety)Fatigue is a major safety concern in many fields, but especially in transportation, because fatigue can result in disastrous accidents. Fatigue is considered an internal precondition for unsafe acts because it negatively affects the human operator's internal state...
- MalaiseMalaiseMalaise is a feeling of general discomfort or uneasiness, of being "out of sorts", often the first indication of an infection or other disease. Malaise is often defined in medicinal research as a "general feeling of being unwell"...
- MicrosleepMicrosleepA microsleep is an episode of sleep which may last for a fraction of a second or up to thirty seconds. Often, it is the result of sleep deprivation, mental fatigue, depression, sleep apnea, hypoxia, narcolepsy, or hypersomnia...
- PresenteeismPresenteeismPresenteeism is the act of attending work while sick. A topic that is at times considered its opposite, absenteeism, has historically received extensive attention in the management sciences, but presenteeism has only recently found a place in the research literature...
- Sleep-deprived driving
- Gaucher's DiseaseGaucher's diseaseGaucher's disease is a genetic disease in which a fatty substance accumulates in cells and certain organs.Gaucher's disease is the most common of the lysosomal storage diseases. It is caused by a hereditary deficiency of the enzyme glucosylceramidase. The enzyme acts on the fatty acid...
External links
- Fatigue — Information for Patients, U.S. National Cancer Institute
- Tiredness — Information leaflet from mental health charity The Royal College of Psychiatrists
- Is exhaustion an actual medical diagnosis? from Slate.com