What is Chronic Fatigue Syndrome (CFS)?
Chronic fatigue syndrome (CFS) is a disease that was first named in the 1980s. Although it is not a new disease, and has been referred to by other names since the 1700s, it still remains the subject of a great deal of controversy. Even now, as increasing numbers of people are being diagnosed with CFS, many people inside and outside the health professions still doubt its existence or maintain that it's a psychological ailment.
But several years of research have confirmed that CFS is indeed a physical illness - just one that's not fully understood. An estimated half a million people in the United States have a CFS-like condition, according to the Centers for Disease Control and Prevention (CDC).
The hallmark symptoms of CFS are overwhelming fatigue and weakness that make it extremely difficult to perform routine and daily tasks, like getting out of bed, dressing, and eating. The fatigue does not get better with bed rest. The illness can severely affect school, work, and leisure activities, and cause physical and emotional symptoms that can last for months or even years.
Chronic fatigue syndrome is more common in females than males and it affects all racial and ethnic groups. CFS usually strikes people between the ages of 20 and 40, but it also occurs in teens. A CFS-like illness also has been determined to occur in children younger than 12. The actual number of children and teens affected by CFS is unknown.
What Causes Chronic Fatigue Syndrome?
The cause of CFS is not yet known. Current research is exploring the possibility that people with CFS may have a dysfunction of the immune and central nervous systems. Scientists are also studying various metabolic abnormalities and risk factors (including genetic predisposition, age, sex, prior illness, environment, and stress) that may affect the development and course of the disease.
Some researchers have suggested that a virus causes CFS, but this theory has not been proved. At one time, researchers thought that Epstein-Barr virus (EBV) played a role in the development of CFS, but many people who are diagnosed with CFS have no evidence of EBV infection. However, a viral cause for CFS is still suspected because the symptoms of CFS often mimic a viral infection, such as chronic infectious mononucleosis. Researchers today are hard at work trying to prove a possible viral link to CFS.
Other theories suggest that one of the following factors may be to blame for CFS:
iron-poor blood (anemia)
low blood sugar (hypoglycemia)
environmental allergies
a body-wide yeast infection
psychiatric or neurological problems
endocrine dysfunction
hypotension (low blood pressure)
Symptoms of Chronic Fatigue Syndrome
Because the symptoms of CFS are so vague and can vary widely from person to person, the CDC developed a detailed case definition in 1994 to help doctors diagnose it. According to that definition, in order to be diagnosed with CFS a person must have both:
severe, chronic fatigue for at least 6 months or longer that is not alleviated by rest, with other known medical conditions having been excluded by a doctor's diagnosis
four or more of the following symptoms:
forgetfulness or difficulty concentrating
sore throat
tender lymph nodes in the neck or armpit
muscle pain or multi-joint pain without swelling
headaches of a new type, pattern, or severity
unrefreshing sleep and vague feelings of illness or depression after exerting oneself, lasting more than 24 hours following exertion
tiredness that lasts longer than 24 hours
In addition, any of the above symptoms associated with the fatigue must have occurred for at least 6 or more months in a row. Also, continuous fatigue should have been the first noticeable symptom of illness.
Other symptoms of CFS can include mild fever, blurry vision, chills, night sweats, diarrhea, and fluctuations in appetite and weight.
