To the practitioner of Chinese medicine the tongue is a tool which they can use to aid in making a diagnosis when using a traditional form of Chinese medicine such as acupuncture or herbal remedies. The tongue is supplied by both the nervous system and the circulatory system and is constantly bathed in saliva; it contains water, mucous, enzymes and electrolytes.

Due to this, the tongue is a very sensitive organ and is one organ which can change depending on how we feel and the state of our health. Therefore, the Chinese believe that by observing the tongue we can find a great deal out about our body and our health, when the practitioner asks you to stick out your tongue they check the appearance of it in three different areas.