Finally, a Blood Test to Diagnose Chronic Fatigue Syndrome

Researchers have brought us one step closer to quickly diagnosing this elusive disease that many brush off as imaginary.

by Lara DeSanto Health Writer

Chronic fatigue syndrome (CFS) is a serious condition that is notoriously difficult to diagnosis — despite the fact that more than 2 million people in the United States have it. But now, researchers at Stanford University School of Medicine may have come up with a blood test to reliably diagnose the disease.

Often shrouded in stigma as an “invisible illness,” the exhaustion and unexplained pain that often come with CFS can seriously impact patients’ quality of life, according to the National Institute of Health (NIH). But there’s currently no way to diagnose the disease other than ruling out all other possibilities, which can make the road to finding relief unnecessarily long and frustrating.

For example, if a patient has symptoms of CFS, a doctor may run tests on organ function and blood and immune-cell counts, said senior study author Ron Davis, Ph.D., professor of biochemistry and of genetics at Stanford, in a press release. "All these different tests would normally guide the doctor toward one illness or another, but for chronic fatigue syndrome patients, the results all come back normal," he said. "Too often, this disease is categorized as imaginary.”

After watching his own son battle CFS for a decade, Dr. Davis set out to address the need for a better means of diagnosis. He and his colleagues have developed a blood test, based on how a person’s immune cells respond to stress, that successfully identified people who had CFS. They took blood samples from 40 people, 20 of whom had CFS and 20 of whom didn’t, and the test correctly flagged the participants with CFS.

Imaginary No More

The success of this new blood test, still in its pilot phase, is long-awaited “scientific evidence that this disease is not a fabrication of a patient's mind,” Dr. Davis said. “We clearly see a difference in the way healthy and chronic fatigue syndrome immune cells process stress."

And the good news doesn’t end there: The Stanford team’s research may also lead to the identification of medications that can help treat CFS. Currently, treatment options for CFS are scarce and mainly involve trying to manage the most troubling symptoms, according to the Centers for Disease Control and Prevention. For example, extreme fatigue may first be addressed by working to improve sleep habits and quality.

The next steps for the researchers are to confirm the findings of their study in a larger study. And the drugs they are testing for potential treatments are all already approved by the Food and Drug Administration or will soon be available to the public, so researchers are hopeful the process will go quickly.

Chronic Fatigue Syndrome vs. Other Causes of Fatigue

The tricky thing about fatigue is that it’s a common symptom of countless different health problems, including CFS. Some of the more obvious culprits include sleep disorders, malnutrition, and anemia, while the less obvious include depression, thyroid problems, and diabetes, according to the NIH.

But the fatigue that comes with CFS is distinct in several ways. Typically, CFS isn’t diagnosed until you’ve been struggling with it for at least six months and find that rest doesn’t improve your symptoms. Additionally, CFS-related fatigue may get worse with physical activity—whereas exercise typically increases energy levels in people dealing with depression and stress.

When your tiredness doesn’t go away with better sleep (these sleep hygiene tips are a great place to start), good nutrition, and a low-stress environment, the next step is to see your doctor for a check-up. They can help you rule out more serious underlying issues and help determine whether you have CFS.

Lara DeSanto
Meet Our Writer
Lara DeSanto

Lara is a former digital editor for HealthCentral, covering Sexual Health, Digestive Health, Head and Neck Cancer, and Gynecologic Cancers. She continues to contribute to HealthCentral while she works towards her masters in marriage and family therapy and art therapy. In a past life, she worked as the patient education editor at the American College of OB-GYNs and as a news writer/editor at