It is often dismissed as being all in the mind. But Chronic Fatigue Syndrome is real, doctors said today.
They have shown that people with symptoms of the debilitating condition have a specific chemical signature in their blood.
Bizarrely, the changes echo those seen in hibernating animals.
The discovery that CFS leaves telltale signs in the blood paves the way for better diagnosis and treatment.
The illness blights the lives of hundreds of thousands of people worldwide.