How is pediatric ME/CFS diagnosed?

Pediatric Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is diagnosed by exclusion. Because there is no test or biomarker for ME/CFS, the diagnosing physician must rule out other illnesses which may cause symptoms similar to those of ME/CFS. The main difference between the adult and pediatric definitions is that pediatric ME/CFS patients can receive provisional diagnosis after 3 months of ongoing fatigue that results in substantial reduction in activity and is not alleviated by rest, and the concurrent existence of post-exertional malaise, unrefreshing sleep, pain, neurocognitive symptoms, and autonomic, neuroendocrine or immune manifestations. Pediatric ME/CFS Diagnosis has more detailed information, further reading, and checklists.