Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Current Stage of Knowledge and Research – Facts and Assumptions

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic multisystem disorder characterized by persistent, debilitating fatigue lasting at least over six months and affecting multiple organ systems. Despite its classification by the WHO as a neurological disease since 1969, the precise pathogenesis remains unclear, and no definitive biomarkers exist. ME/CFS primarily affects adults aged 30–50, predominantly women, often triggered by infections such as Epstein–Barr virus or SARS-CoV-2, with a rising incidence following the COVID-19 pandemic. Diagnosis is complex and based on exclusion of other conditions, relying heavily on clinical criteria, particularly the hallmark symptom of post-exertional malaise (PEM), a delayed, severe worsening of symptoms following exertion. The Canadian Consensus Criteria are commonly used in Europe, requiring at least five major and two of three minor criteria, including neurological, autonomic, and immunological disturbances. Currently no causal, evidence-based cure exists. Treatment focuses on symptom management and patient education. The basic principle is the control of physical and mental activities and a careful energy management to avoid PEM, alongside supportive measures such as sleep hygiene, pain management, and psychosocial care. Pharmacological interventions address specific symptoms, with limited evidence for efficacy. Severe cases pose significant care challenges. ME/CFS represents a substantial burden on patients and families, compounded by delayed diagnosis, lack of specialized care, and societal under-recognition. The current research aims to clarify pathophysiological mechanisms and identify biomarkers to enable targeted therapies. Until then, multidisciplinary, evidence-based management and improved awareness are essential to mitigate the disease’s profound impact.