Idiopathic chronic fatigue (ICF), is characterized by unexplained fatigue that lasts at least six consecutive months. It is widely understood to have a profound effect on the lives of patients who experience it. ICF is a common illness of unknown origin, and remains poorly understood.

Classification

Idiopathic chronic fatigue is classified as a physical medical condition of unknown origin by the

World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of h ...

Diagnosis

ICF is fatigue of unknown origin, persisting or relapsing for a minimum of six consecutive months, and failing to meet the criteria for

chronic fatigue syndrome Chronic fatigue syndrome (CFS), also called myalgic encephalomyelitis (ME) or ME/CFS, is a complex, debilitating, long-term medical condition. The causes and mechanisms of the disease are not fully understood. Distinguishing core symptoms are ...

. There are no agreed upon international criteria for idiopathic chronic fatigue, however the CDC's 1994 Idiopathic Chronic Fatigue criteria, known as the Fukuda criteria, are commonly used.

Signs and symptoms

* Clinically evaluated fatigue * New or definite onset (not lifelong) * Not resulting from exertion * Fatigue persists or is relapsing for six consecutive months or longer * Fails to meet the criteria for

* The cause is unknown

Exclusions

* Fatigue which begins within 2 years of a

substance use disorder Substance use disorder (SUD) is the persistent use of drugs (including alcohol) despite substantial harm and adverse consequences as a result of their use. Substance use disorders are characterized by an array of mental/emotional, physical, and ...

(addiction) or at any time after *

major depression Major depressive disorder (MDD), also known as clinical depression, is a mental disorder characterized by at least two weeks of pervasive low mood, low self-esteem, and loss of interest or pleasure in normally enjoyable activities. Introdu ...

with psychotic or melancholic features *

bipolar disorder Bipolar disorder, previously known as manic depression, is a mental disorder characterized by periods of depression and periods of abnormally elevated mood that last from days to weeks each. If the elevated mood is severe or associated with ...

schizophrenia Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social withdra ...

or schizophrenia-related disorders * delusional disorders * the eating disorder

bulimia nervosa Bulimia nervosa, also known as simply bulimia, is an eating disorder characterized by binge eating followed by purging or fasting, and excessive concern with body shape and weight. The aim of this activity is to expel the body of calories eate ...

dementia Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...

of any form *

fatigue Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...

caused by an active medical condition *

caused by a previous medical condition that may not be fully resolved * fatigue caused as a known side effect of medication * severe obesity (a

body mass index Body mass index (BMI) is a value derived from the mass (weight) and height of a person. The BMI is defined as the body mass divided by the square of the body height, and is expressed in units of kg/m2, resulting from mass in kilograms and he ...

greater than 45)

Common medical causes of fatigue

These must be ruled out before a diagnosis of ICF can be made. * Infectious diseases including viruses and TB * Vascular diseases (affecting heart and circulation) * Toxins and drug effects including poisons and substance use (addiction) * Diseases affecting the lungs, including

chronic obstructive pulmonary disease Chronic obstructive pulmonary disease (COPD) is a type of progressive lung disease characterized by long-term respiratory symptoms and airflow limitation. The main symptoms include shortness of breath and a cough, which may or may not produce ...

(COPD) * Endocrine and metabolic problems, e.g., thyroid diseases and diabetes * Diseases involving benign or cancerous tumours, including

cancer fatigue Cancer-related fatigue is a 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 of most fo ...

* Psychological or psychosocial conditions, including

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 ...

Lupus Lupus, technically known as systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Comm ...

and certain autoimmune or neurological diseases * Occupational stress or other life stress and burnout *

Domestic violence Domestic violence (also known as domestic abuse or family violence) is violence or other abuse that occurs in a domestic setting, such as in a marriage or cohabitation. ''Domestic violence'' is often used as a synonym for ''intimate partner ...

Management

Idiopathic chronic fatigue is typically managed in general medicine rather than by referral to a specialist. There is no cure, no approved drug, and treatment options are limited. Management may involve a form of counseling, or antidepressant medication, although some patients may prefer herbal or alternative remedies.

Counseling

A form of counseling known as

cognitive behavioral therapy Cognitive behavioral therapy (CBT) is a psycho-social intervention that aims to reduce symptoms of various mental health conditions, primarily depression and anxiety disorders. CBT focuses on challenging and changing cognitive distortions (suc ...

may help some people manage or cope with idiopathic chronic fatigue.

Medication

There are no approved drugs for ICF.

Anti-depressants

Antidepressants drugs such as

tricyclic antidepressant Tricyclic antidepressants (TCAs) are a class of medications that are used primarily as antidepressants, which is important for the management of depression. They are second-line drugs next to SSRIs. TCAs were discovered in the early 1950s and wer ...

s (TCAs) or

selective serotonin reuptake inhibitor Selective serotonin reuptake inhibitors (SSRIs) are a class of drugs that are typically used as antidepressants in the treatment of major depressive disorder, anxiety disorders, and other psychological conditions. SSRIs increase the extracell ...

s (SSRIs) may be appropriate.

Alternative and complementary treatments

Only limited trials had been conducted for alternative and complementary treatments; there is no clear evidence of these treatments being effective for ICF due to a lack of randomized controlled trials.

Prognosis

Over half of patients remain fatigued after one year.

Epidemiology

Fatigue is common in the general population and often caused by overwork, too much activity or a specific illness or disease. Around 20% of patients who visit their clinician report fatigue. Prolonged fatigue is fatigue that persists for more than a month, and chronic fatigue is fatigue that lasts at least six consecutive months. Idiopathic chronic fatigue affects between 0.62% and 6.42% of patients, with females more likely to be affected than men. Age at onset is typically between age 15 and 24, or over 60 years of age. A significant number of patients present with idiopathic chronic fatigue as part of a mix of symptoms, while others present with a primary problem of fatigue alone.

References

External links

{{Medical resources, ICD10={{ICD10, R, 53, 82 , ICD9={{ICD9, 780.79 , ICD10-CA={{ICD10, R, 53 , ICD11={{ICD11, MG22, SNOMED CT=, MeshID=, DiseasesDB= Idiopathic diseases