Chronic fatigue syndrome defies physicians.

Once dismissed as "Yuppie flu" or merely a figment of a stressed-out population's imagination, Chronic Fatigue Syndrome (CFS) has come to be recognized as a very real medical problem that causes major difficulties for its victims. Moreover, it is not a new disease, but probably has been around since the time of Hippocrates, notes Douglas Fine, professor of medicine, University of Oklahoma Health Sciences Center.

As its name suggests, CFS is characterized by severe, ongoing fatique, and patients often are diagnosed with mononucleosis. One of the first clues that the cause actually may be CFS is when the symptoms do not resolve as most acute infections do. "It is not unusual for a patient to tell you, `On Friday, September 13, at 4 p.m., I began experiencing chills and fever, and I have not been the same since.' The second major indicator is that bed rest fails to solve the problem."

Additional symptoms include sore throat, muscle weakness, headache, sleep disturbance, excessive fatigue after exertion, irritability, confusion, depression, anxiety or panic attacks, difficulty in concentrating, and problems adjusting to bright lights. For the symptoms to be considered related to chronic fatigue, a person must experience more than six symptoms for a period or more than six months.

The typical CFS patient is in the mid to late 30s, but the disease has stricken patients ranging from 11 to 60 years of age. Women contract it twice as often as men, and the typical victim is white, middle-class, and urban...