Iranian traditional medicine (ITM) (Persian: طب سنتی‌ ایرانی‎, romanized: tebbe sonnati-e irāni), also known as Persian traditional medicine or Iranian traditional medicine, is one of the most ancient forms of traditional medicine. ITM is grounded in the concept of four humors: phlegm (Balgham), blood (Dam), yellow bile (Ṣafrā') and black bile (Saudā') .The four humors concept is based on the teachings of Rhazes and Avicenna into an elaborate medical system.