PT - JOURNAL ARTICLE AU - Fatima Amar Bahowairath AU - Nicholas Woodhouse AU - Samir Hussain AU - Mujahid Al Busaidi TI - Lesson of the month 1: Subacute thyroiditis: a rare cause of fever of unknown origin AID - 10.7861/clinmedicine.17-1-86 DP - 2017 Feb 01 TA - Clinical Medicine PG - 86--87 VI - 17 IP - 1 4099 - http://www.rcpjournals.org/content/17/1/86.short 4100 - http://www.rcpjournals.org/content/17/1/86.full SO - Clin Med2017 Feb 01; 17 AB - Fever of unknown origin (FUO) is sometimes a diagnostic dilemma for clinicians. Endocrine causes reported in the literature include subacute thyroiditis, thyrotoxicosis, adrenal insufficiency and pheochromocytoma. Among these, subacute thyroiditis is often overlooked as it can occasionally lack typical symptoms. This case illustrates the fact that subacute thyroiditis should be considered as a possible cause of fever even if signs and symptoms of hyperthyroidism and thyroid tenderness are absent.