Sarcoidosis-associated fatigue is globally recognised as a disabling symptom. Fatigue has been reported in up to 50-70% of sarcoidosis patients, causing impaired quality of life. The aetiology of this troublesome problem remains elusive and is usually multifactorial. Fatigue can be a consequence of treatment itself, including as a complication of corticosteroid therapy. The diagnosis of sarcoidosis-associated fatigue requires an extensive evaluation to identify and treat potentially reversible causes. Granuloma formation and cytokine release may be involved in its aetiology. However, despite adequate sarcoidosis treatment, many patients continue to experience fatigue. Comorbidities associated with sarcoidosis, including depression, anxiety,...