Tongue diagnosis in Chinese Medicine is a method of diagnosing disease and disease patterns by visual inspection of the tongue and its various features. It is one of the major diagnostic methods in Chinese Medicine since the time of the Yellow Emperor's Inner Classic.[1] It is considered a part of the “Inspection” method within the four methods of diagnosis.[2] Practitioners claim that the tongue provides important clues reflecting the conditions of the internal organs. Like other diagnostic methods in Traditional Chinese Medicine, tongue diagnosis is based on the “outer reflects the inner” principle, which is that external structures often reflect the conditions of the internal structures and can give us important indications of internal disharmony.[2]