Kumar, C VijaiAlex, Neetu Mariam2023-08-092023-08-092023-06Kumar C Vijai, Alex Neetu Mariam. An Interesting Endocrine Cause of Pyrexia of Unknown Origin: A Case Report and Review of Literature. Indian Journal of Clinical Practice. 2023 Jun; 34(1): 25-260971-0876http://imsear.searo.who.int/handle/123456789/222131Pyrexia of unknown origin (PUO) is one of the most challenging medical problems. Endocrine causes of PUO are rare. Fever is common in a few endocrine disorders (e.g., thyroid storm, adrenal crisis and pheochromocytoma). However, PUO as the sole presenting feature is very rare with only a few reported cases in the literature. We present the case of a middle-aged male who came to us with PUO, weight loss and loss of appetite. The unusual symptomatology like loss of appetite, altered bowel habits made diagnosis difficult. This case highlights the importance of considering thyroid disorder in the differential diagnosis of PUO. Abnormal thyroid function may be an early clue for diagnosis.Pyrexia of unknown originhyperthyroidismendocrine disordersJournal ArticleIndiaSenior ConsultantRegistrar Dept.of Internal Medicine, Apollo Hospitals, Chennai, Tamil Nadu, India