Chronic Fatigue Syndrome

Fatigue is one of the most common presenting complaints in primary care and poses a significant diagnostic challenge due to its multifactorial aetiology. While the majority of cases are benign and self-limiting, fatigue may also represent an early manifestation of serious underlying pathology. This review distinguishes between acute fatigue, typically transient and associated with intercurrent illness or lifestyle factors, and chronic fatigue, defined as fatigue persisting for six or more weeks, which is more likely to be multifactorial in origin.

This narrative review aims to provide a practical and structured diagnostic framework for general practitioners to evaluate and manage fatigue effectively in the primary care setting.

A narrative review of the literature was conducted using PubMed and Google Scholar. Searches were limited to articles published in English from 2010 onwards. Search terms included "fatigue," "primary care," "chronic fatigue," "myalgic encephalomyelitis," "post-viral fatigue," "sleep disorders," and "functional somatic syndromes." Seminal references predating 2010 were retained where no suitable replacement was available. This review did not employ a formal systematic search strategy, and no risk-of-bias assessment was performed, consistent with the narrative review format.

Fatigue arises from a wide range of physical, psychological, and lifestyle-related causes, best understood through a three-tier classification: primary/idiopathic, secondary, and psychosocial. A systematic approach incorporating thorough history-taking, focused clinical examination, and judicious use of investigations is essential. Identification of red flag symptoms is critical to exclude serious conditions, including malignancy and chronic infections.

A structured, patient-centred approach enables general practitioners to manage fatigue effectively while minimising unnecessary investigations and ensuring timely identification of serious disease.