The cause of chronic fatigue syndrome is not known. There are no specific diagnostic tests for the illness which can begin suddenly - often after a trauma or a case of the flu - or develop gradually. Symptoms linger for at least six months and often for years.
Some studies have found a greater prevalence of allergy in patients with the syndrome, and various immunological findings have been described.
"Nature is not giving up its secrets all that easily when it comes to chronic fatigue syndrome," says Dr. Arthur Lawrence, assistant surgeon general at Department of Health and Human Services in Washington, D.C.
Numbers of people affected are hard to pin down. Centers for Disease Control and Prevention estimate that there are at least four to 10 cases per 100,000 adults in the United States. As many as several hundred thousand Americans are thought to have the disease. About 80 percent of them are women. Because the illness is difficult to diagnose, it frequently is met with skepticism.
"It can often be difficult to convince family and friends that there is something wrong," Stoner says.
For 48-year-old Richard Guhr of Hagerstown, the hardest part of having chronic fatigue syndrome is that it is not a very visible disease. He believes people think he's a hypochondriac.
Although medicine hasn't found a cause or specific laboratory test, chronic fatigue syndrome isn't an imagined disease, Lawrence says.
Chronic fatigue syndrome is being taken seriously at the federal level.
In May there will be an organizational meeting of a new official advisory commission composed of scientists and people representing the disabled.
Lawrence calls it a cross-disciplinary approach to getting good minds working together on a tough subject.
On a local level, people are working together in a support group. Susan Chamblin of Hagerstown leads a monthly fibromyalgia/chronic fatigue syndrome support group at Washington County Free Library. She says the support group has become her avocation, and she is a rich source of up-to-date information about the diseases which share many of the same debilitating symptoms.
Chamblin says there are about 150 people in the area who have attended or contacted her about the group since it started - initially in Martinsburg in 1989. You don't have to be diagnosed to attend, and meetings are confidential.
Both Stoner and Guhr attend meetings of the support group.
"To keep your psychological well- being, you need some regular contact with other people who have it," Stoner says.
Guhr says he was a perfectionist, an active, organized person before 1989 when he got sick. He says the change in him is like day and night. His self-esteem is down, but he says the support group helps.
"We're all in the same boat. There are times when we do help one another."