FORT LAUDERDALE, Fla. — Marly Silverman had a high-energy job as a financial consultant to a major U.S. bank, until she came down with a viral infection that she couldn't seem to shake. She was exhausted all the time, ran a low-grade fever and lost weight, and then the neurological symptoms began.

"I would be driving on I-95 and forget where I was going — not a good thing," said Silverman, 52.

It took several months, but eventually she was diagnosed with chronic fatigue syndrome, the Rodney Dangerfield of diagnoses.

For years, people who complained of the symptoms — exhaustion, joint pain, sleep problems, impaired memory, inability to concentrate — were dismissed by some doctors as malingerers or hypochondriacs.

This month, the federal Centers for Disease Control and Prevention launched a campaign to change that by educating patients and physicians that chronic fatigue syndrome, or CFS, is a mysterious but serious disease sometimes triggered by a viral infection but with other unknown factors.

It affects at least 1 million Americans, but many have not been diagnosed because most doctors have not been trained to recognize it, said Dr. William Reeves, chief of the chronic viral diseases branch at the Centers for Disease Control. Women are affected at about four times the rate as men, and non-white women are affected at a rate greater than white women, Reeves said. The age group most affected is 40 to 59.

Reeves, who leads a research group studying the syndrome, said the illness follows a pattern of symptoms that can change over time, and that sometimes disappear and then come back. Spontaneous recovery is rare, he said.

Treatment plans typically involve doctors asking patients which symptoms most affect their quality of life — such as sleeplessness, joint pain, gastrointestinal complaints or depression — and prescribing medications to ease those symptoms.

Irwin Auster, who facilitates some of the meetings, said he sought help from a dozen different doctors for his unexplained physical pain, but none could figure out what was causing it or give him anything strong enough to take it away.

"I was on the verge of ending my life, by sitting on the tracks and waiting for the train," said Auster, 64.

Then he read an article about Dr. Nancy Klimas, a University of Miami School of Medicine clinician-researcher, who treats patients with symptoms like his.

"I do owe her my life," Auster said. "I really do."

Klimas, who was in Washington for the launch of the CDC campaign, said research over the past 20 years is beginning to figure out the biological underpinnings of the syndrome, which she thinks is badly misnamed.

"If it were called chronic neuroinflammatory disease, then people would get it," she said. "Up until now nobody's been willing to change the name, but now there's proof (that inflammation occurs in the brain.)

"There's evidence that the patients with this illness experience a level of disability that's equal to that of patients with late-stage AIDS, patients undergoing chemotherapy, patients with multiple sclerosis."

Klimas is president of the International Association for Chronic Fatigue Syndrome, an organization of medical professionals and research scientists. Its next research conference will be in January in Fort Lauderdale.

She and other investigators have shown that different types of cells within the immune system are abnormal either in number or their capacity to function in these patients.

University of Miami researchers, including Mary Ann Fletcher, have just been awarded new grants from the National Institutes of Health to continue their work. One goal is to come up with tests to diagnose the disease in its different forms, Fletcher said.

"We have fairly good reason to believe that CFS is not a homogeneous syndrome. There may be several subsets, and it's important to compare apples to apples. It's possible a treatment that would work for subset A would not work for subset B," Fletcher said.

Klimas and Fletcher are recruiting 150 new patients for a study that will assess them on days when they feel good and also when they're feeling particularly bad, so they can compare their blood samples for differences.

"And if on a bad day they are unable to come to the clinic, we will send somebody to them to draw their blood," Fletcher said.

Klimas said even though researchers still don't have all the answers, there are effective treatment strategies that do help patients.