Fatigue in Other Medical Disorders Hashir Majid, MD a, *, Munira Shabbir-Moosajee, MD a , Sarah Nadeem, MD b We review fatigue and sleepiness caused by renal, hematological, and endocrine diseases in this article. RENAL DISORDERS Both acute and chronic kidney disease are associ- ated with symptoms of fatigue, lethargy, and mal- aise. 1,2 There is no specific treatment for fatigue in renal diseases. Management focuses on treating the underlying etiology of the kidney disease and preventing progression of renal dysfunction, if possible. Supportive measures, including medical therapy and dialysis, may need to be initiated. Because most available data pertain to symptoms in chronic renal failure, most of this section fo- cuses on fatigue in chronic kidney disease (CKD). FATIGUE IN CHRONIC KIDNEY DISEASE Fatigue is the initial and one of the cardinal mani- festations of CKD. 1,3 This is irrespective of the eti- ology of CKD. Unlike healthy individuals, in whom fatigue can be a protective mechanism aimed at obtaining rest and replenishment to overcome physical and mental stress, fatigue in medical dis- orders can be severely debilitating. 4 In CKD, it has significant impact on quality of life and is associ- ated with substantial morbidity and mortality. 5,6 CKD is divided into 5 stages based on the glomer- ular filtration rate (GFR). 7 The initial stages (stages 1 and 2) are mostly asymptomatic. Clinical manifesta- tions, including fatigue, generally first become apparent with a drop in GFR below 60 mL/min/ 1.73 m 2 (stage 3 CKD). Symptoms are generally progressive unless appropriate management of CKD is initiated. Even with optimal therapy, many patients continue to experience malaise/fatigue. The pathogenesis of fatigue in CKD is multifac- torial. Anemia, disordered calcium and phosphate metabolism, wasting, and depression are all impli- cated (see Table 1). 8 Anemia in Chronic Kidney Disease Anemia is common in patients with CKD. 9 More than half of patients with advanced-stage CKD have low hemoglobin levels. 10 The authors have no conflicts of interest to disclose. a Department of Medicine, Aga Khan University, PO Box 3500, 1st Floor, FOB Building, Karachi 74800, Pakistan; b Dreyer Medical Clinic, 1870 W Galena Boulevard, Aurora, IL 60506, USA * Corresponding author. E-mail address: hashir.majid@aku.edu KEYWORDS  Fatigue  Chronic kidney disease  Endocrine disorders  Anemia  Parathyroid  Thyroid  Hematological disorders  Cancer KEY POINTS  Fatigue associated with medical disorders can have a significant impact on functional status, quality of life, and clinical outcomes.  A variety of medical diseases can be associated with fatigue, including renal, hematological, and endocrine pathologies.  The pathophysiology of fatigue and sleepiness in the setting of some common medical problems is discussed in this review.  Treatment focuses on correction of the underlying medical disorder. Sleep Med Clin 8 (2013) 241–253 http://dx.doi.org/10.1016/j.jsmc.2013.02.007 1556-407X/13/$ – see front matter Ó 2013 Elsevier Inc. All rights reserved. sleep.theclinics.com