RESUMO
Hypothyroidism (Qillat-e-Ifraz-e-Darqiyya) is a condition where the thyroid gland is underactive and unable to produce enough thyroid hormone. The description of hypothyroidism as a disease is not directly found in Unani texts. However, the signs and symptom of hypothyroidism resemble the clinical manifestation associated with Su-e-Mizaj Barid Maddi (derangement in cold temperament), such as plethora (Imtila), excessive salivation (Kasrat-e-Luabe-e-Dahan), tiredness (Aa'yan), loss of appetite (Zoaf-e-Ishteha), excessive sleeping (Kasrat-e-Naum) and cold skin (Baroodat-e-Jildia). These signs and symptoms are the result of an excess in abnormal phlegm (Ghair Tabayi Balgham) in the body. This review article identifies the observations from Unani literature that describe derangement in cold temperament and relate them to the clinical presentation of primary hypothyroidism in conventional medicine. We also discuss management of these symptoms in Unani medicine.