[Endocrine and other medical causes of abnormal fatigability]

Many endocrine diseases can cause fatigue. Tiredness is a frequent symptom of primary and secondary hypothyroidism, hyperthyroidism, excessive glucocorticoid or mineralocorticoid production, primary and secondary adrenal insufficiency, primary and secondary hypogonadism and hyperprolactinemia in the male, acromegaly, diabetes mellitus and diabetes insipidus. A great number of medical diseases other than those mentioned in the articles on cardiological and pneumological fatigue can also cause abnormal tiredness (infectious diseases, hematological, renal, hepatic, gastrointestinal and rheumatological disturbances, vasculitis and malignant tumors). The pathogenesis of tiredness caused by endocrine or medical illnesses, i.e. how the sensation of fatigue is produced, is not clear. The fatigue of the various endocrine or other medical diseases is not disease-specific, i.e. its characteristics do not differentiate it from the fatigue of other illnesses.