January 14, 2005
Chronic Fatigue Syndrome
January 12, 2005 KidsHealth.org
Sixteen-year-old Samantha is always exhausted. For months she's had swollen glands and weakness. She has difficulty concentrating in school, frequently has headaches, and finds it hard to get out of bed most mornings. Although Samantha's parents suspect she's involved in too many activities, they have also begun to worry because her grades have plummeted and her symptoms have worsened.
When Samantha and her parents visit the doctor to try to find out what's wrong, the doctor takes a detailed history of Samantha's symptoms, paying careful attention to how long they have been going on. After a full physical examination and several blood tests, it is determined that Samantha has a condition known as chronic fatigue syndrome (CFS).
What Is Chronic Fatigue Syndrome?
Chronic fatigue syndrome is a noncontagious disease that was first recognized as a physical illness in the 1980s and remains the subject of a great deal of controversy. Even now, as increasing numbers of people are being diagnosed with the disease, there are still many people inside and outside the health professions who 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. According to the U.S. Centers for Disease Control and Prevention (news - web sites) (CDC), it is estimated that as many as half a million people in the United States have a CFS-like condition.
The hallmark of CFS is symptoms of 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 severely impacts school, work, and pleasurable activities, causing 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. Most people experience this illness between the ages of 20 and 40, but the disorder also occurs in adolescents. A CFS-like illness has also been determined to occur in children younger than 12. The actual number of children and teens affected by CFS illness 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 proven. 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)
a body-wide yeast infection
psychiatric or neurological problems
Because the symptoms of CFS are so vague and can vary widely from person to person, the CDC developed a detailed case definition in 1993 to help doctors diagnose the condition. According to that definition, a person must have both of the following in order to be diagnosed with CFS: a person must have severe, chronic fatigue for at least 6 months or longer, with other known medical conditions having been excluded by a doctor's diagnosis, and at the same time, an individual must have four or more of the following symptoms:
forgetfulness or difficulty concentrating
tender lymph nodes in the neck or armpit
muscle pain or multi-joint pain with swelling or redness
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
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.
Difficulty Diagnosing CFS
Chronic fatigue syndrome is hard to diagnose because a single diagnostic test does not exist, and there is no identifiable cause of the illness. Another problem is that symptoms of CFS often mimic other disorders such as viral infections, kidney disease, cardiac disease, depression, and neurological illnesses. CFS is a diagnosis of exclusion, which means that doctors first have to make sure that a person's fatigue and other symptoms are not caused by another illness, a sleep disorder, or hormone problems such as hypothyroidism.
"We all get tired, depressed, and run down," says Joel D. Klein, MD, an infectious diseases specialist. But CFS is different from normal feelings of fatigue and low energy. "Symptoms of CFS often develop suddenly and include a strong, noticeable fatigue which comes and goes or remains for months," Dr. Klein explains.
Posted by Nancy at January 14, 2005 06:44 AM