Diagnosis and management of chronic fatigue syndrome or myalgic encephalomyelitis (or encephalopathy): summary of NICE guidance

Data from other countries indicate that chronic fatigue syndrome (also known as myalgic encephalomyelitis or myalgic encephalopathy) (CFS/ME) is relatively common (affecting at least 0.2-0.4% of the population), although good epidemiological data for the United Kingdom are lacking. Many different potential aetiologies for CFS/ME have been investigated, including neurological, endocrine, immunological, genetic, psychiatric, and infectious, but the aetiology cannot yet be fully explained. CFS/ME can cause prolonged illness and disability and substantially affect patients and their families. Although most patients have mild or moderate symptoms, some have severe CFS/ME and are housebound or even unable to move from their bed. Uncertainties about diagnosis and management may exacerbate the impact of symptoms, and patients often encounter delays in diagnosis and difficulty accessing information, support, and potentially helpful therapies.1 This article summarises the most recent guidance from the National Institute for Health and Clinical Excellence (NICE) on diagnosing and managing this condition.2 NICE recommendations are based on systematic reviews of best available evidence. When minimal evidence is available (as with CFS/ME), a range of consensus techniques is used to develop recommendations. In this summary, recommendations derived primarily from consensus techniques are indicated with an asterisk (*). ### General principles