Recent Articles
- What Causes Insomnia?
- Symptoms of Insomnia
- Types of Insomnia
- Key Points About Insomnia
- What is Insomnia and Who is at Risk?
- Diagnosing Chronic Fatigue Syndrome
- What is Chronic Fatigue Syndrome?
- Who is at Risk for Narcolepsy?
- Who is at risk for Sleep Apnea?
- Who is at Risk for Restless Legs Syndrom
- What is Sleep Apnea?
- What is Restless Legs Syndrome
- What is Narcolepsy?
- What Causes Sleep Apnea
- What Causes Restless Legs Syndrome?
- What Causes Narcolepsy?
- The Signs and Symptoms of Sleep Apnea
- Signs and Symptoms of Restless Legs Syndrome
- Signs and Symptoms of Narcolepsy
- Key Points on Sleep Apnea
- Restless Legs Syndrome - Points to Remember
- Key Points about Narcolepsy
- Living With Sleep Apnea
- Living With Restless Legs Syndrome
- Living With Narcolepsy
- Insomnia Overview
- How is Sleep Apnea Treated?
- How is Sleep Apnea Diagnosed?
- Treating Restless Legs Syndrome
- How is Restless Leds Syngrome Diagnosed
- Treating Narcolepsy
- How is Narcolepsy Diagnosed
- Treating Insomnia
- How is Fibromyalgia Treated?
- What Causes Fibromyalgia?
- Who is affected by Fibromyalgia?
- What is Fybromyalgia?
Support Groups
Share your health experiences and concerns with others. Find out More...Drugs & Treatments
Search and rate treatments to help others like you. Find out More...What is Chronic Fatigue Syndrome?
What is Chronic Fatigue Syndrome?
Chronic fatigue syndrome (CFS) is a debilitating and complex syndrome that involves multiple body systems. It is characterized by profound fatigue that is not improved by bed rest and may be exacerbated or re-kindled by physical or mental activity. Persons with CFS most often function at substantially lower levels of activity from their pre-onset capacities. In addition to these defining characteristics, a diverse array of other symptoms is associated with CFS; these symptoms include cognitive deficits, impaired sleep, myalgia, arthralgia, headache, gastrointestinal symptoms, and tender lymph nodes.
Neither a specific cause(s) nor any specific diagnostic test(s) have been identified for this illness. The range of symptoms, however, suggests there may be subtle perturbations in multiple physiological pathways that are triggered by diverse causes such as infection, stress, brain structure abnormalities, hormone levels, proinflammatory cytokines, etc. Epidemiological evidence is also limited and requires further study. Existing data suggest, however, that CFS occurs three to four times more frequently among women than among men and 10 times more often in white Americans than in Americans of other racial/ethnic groups. A more recent study disputes these numbers and would narrow the gap between the sexes, as well as among racial/ethnic population subgroups.
The cluster of symptoms we know as CFS has been described over the years under many names with varying definitions and suspected causes. But it was not until 1988 that a formal case definition emerged.
Chronic fatigue syndrome—a formal case definition from the United StatesIn 1988, in an effort to standardize research definitions, a group of experts led by the Centers for Disease Control and Prevention (CDC) proposed a new name for Epstein-Barr virus syndrome that more accurately described it: chronic fatigue syndrome. The new definition outlined two major criteria:
- Persistent or relapsing, debilitating fatigue, lasting at least 6 months, in a person who has no previous history of similar symptoms; and
- Exclusion of other clinical conditions that may produce similar symptoms (e.g., malignancy, autoimmune disease, chronic psychiatric disease, and chronic inflammatory disease, among others).
The definition also included the occurrence of at least eight symptoms including mild fever, sore throat, painful lymph nodes, prolonged fatigue after exercise, joint or muscle pain, unexplained muscle weakness, headaches, and sleep disturbance.
CFS—the International definition
In response to criticisms of the original CDC definition of CFS as too ambiguous and over-exclusive, and to facilitate a more systematic collection of data internationally, the International Chronic Fatigue Syndrome Study Group, headed by CDC and including representatives from Australia and Great Britain, proposed a revised CFS case definition in 1994. Known as the Fukuda or research definition, it was based on the presence of the following:
· Clinically evaluated, unexplained, persistent or relapsing chronic fatigue that is of new or definite onset (has not been lifelong); is not the result of ongoing exertion; is not substantially alleviated by rest; and results in substantial reduction in previous levels of occupational, educational, social, or personal activities.
The concurrent occurrence of four or more of the following symptoms, all of which must have persisted or recurred during 6 or more consecutive months of illness and must not have predated the fatigue:
- self-reported impairment in short-term memory or concentration severe enough to cause substantial reduction in previous levels of occupational, educational, social, or personal activities
- tender cervical or axillary lymph nodes
- muscle pain, multijoint pain without joint swelling or redness
- headaches of a new type, pattern, or severity
- unrefreshing sleep
- postexertional malaise lasting more than 24 hours