Chronic fatigue syndrome
Chronic fatigue syndrome (CFS) is a condition that causes extreme tiredness.People with CFS have debilitating fatigue that lasts for six months or longer. They also have many other symptoms. Some of these are pain in the joints and muscles, headache, and sore throat. CFS does not have a known cause, but appears to result from a combination of factors.
CFS is the most common name for this disorder, but it also has been called chronic fatigue and immune disorder (CFIDS), myalgic encephalomyelitis, low natural killer cell disease, postviral syndrome, Epstein-Barr disease, and Yuppie flu. CFS has so many names because researchers have been unable to find outexactly what causes it and because there are many similar, overlapping conditions. Reports of a CFS-like syndrome called neurasthenia date back to 1869.Later, people with similar symptoms were said to have fibromyalgia because one of the main symptoms is myalgia, or muscle pain. Because of the similarityof symptoms, fibromyalgia and CFS are considered to be overlapping syndromes.
In the early to mid-1980s, there were outbreaks of CFS in some areas of the United States. Doctors found that many people with CFS had high levels of antibodies to the Epstein-Barr virus (EBV), which causes mononucleosis, in theirblood. For a while they thought they had found the culprit, but it turned outthat many healthy people also had high EBV antibodies. Scientists have alsofound high levels of other viral antibodies in the blood of people with CFS.These findings have led many scientists to believe that a virus or combination of viruses may trigger CFS.
CFS was sometimes referred to as Yuppie flu because it seemed to often affectyoung, middle-class professionals. In fact, CFS can affect people of any gender, age, race, or socioeconomic group. Although anyone can get CFS, most patients diagnosed with CFS are 25-45 years old, and about 80% of cases are in women. Estimates of how many people are afflicted with CFS vary due to the similarity of CFS symptoms to other diseases and the difficulty in identifying it. The Centers for Disease Control and Prevention (CDC) has estimated that 4-10 people per 100,000 in the United States have CFS. According to the CFIDS Foundation, about 500,000 adults in the United States (0.3% of the population)have CFS. This probably is a low estimate since these figures do not includechildren and are based on the CDC definition of CFS, which is very strict for research purposes.
Although what causes CFS is still controversial, many doctors and researchersnow think that CFS may not be a single illness. Instead, they think CFS maybe a group of symptoms caused by several conditions. One theory is that a microorganism, such as a virus, or a chemical injures the body and damages the immune system, allowing dormant viruses to become active, causing flu-like symptoms. Immune abnormalities have been found in studies of people with CFS, although the same abnormalities are also found in people with allergies, autoimmune diseases, cancer, and other disorders.
The role of psychological problems in CFS is very controversial. Because manypeople with CFS are diagnosed with depression and other psychiatric disorders, some experts conclude that the symptoms of CFS are psychological. However,many people with CFS did not have psychological disorders before getting theillness. Many doctors think that patients become depressed or anxious because of the effects of the symptoms of their CFS.
Having CFS is not just a matter of being tired. People with CFS have severe fatigue that keeps them from performing their normal daily activities, for example, working, attending school, or even taking part in social activities.
CFS is diagnosed by evaluating symptoms and eliminating other causes of fatigue. In the United States, many doctors use the CDC case definition to determine if a patient has CFS.
Diagnosis of CFS is made based on unexplained continuing or recurring chronicfatigue that has lasted for at least six months, that is of new or definiteonset (that is, the person has not been tired their whole life), and that seriously interferes with a person's life. In addition, a patient must have fouror more of the following symptoms: trouble remembering or concentrating; sore throat; tender lymph nodes; muscle pain; pain in many joints without swelling or redness; headaches; unrefreshing sleep; and postexertional malaise (a vague feeling of discomfort or tiredness following exercise or other physicalor mental activity) lasting more than 24 hours. These symptoms must have continued or recurred during six or more consecutive months of illness and must not have started before the fatigue began.
There is no cure for CFS, but treatment is available to help relieve the symptoms. Treatment is usually individualized to each person's particular symptoms and needs. Most doctors recommend a combination of rest, exercise, and a balanced diet. Counseling and stress reduction techniques also may help some people with CFS.
Many nutritional supplements and herbal preparations advertised for treatmentof CFS are unproven, though others seem to provide some people with relief.People with CFS should discuss their treatment plan with their doctors, and carefully weigh the benefits and risks of each therapy before making a decision. Drugs that sometimes alleviate the symptoms of CFS include nonsteroidal anti-inflammatory drugs, low dosages of antidepressants, and antianxiety drugs.Research into the cause and treatment of CFS is continuing.
The course of CFS varies widely for different people. Some people get progressively worse over time, while others gradually improve. Some have periods ofillness that alternate with periods of good health. While many people with CFS never fully regain their health, they find relief from symptoms and adapt to the demands of the disorder by carefully following a treatment plan combining adequate rest, nutrition, exercise, and other therapies.
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