Which part of the tongue is referred to

Tongue moss refers to a layer of moss on the tongue, normal tongue have a layer of thin white moss, generated by the stomach qi. Traditional Chinese medicine (TCM) practitioners can use tongue coating to determine the degree of heat and cold.
Tongue moss is produced by stomach qi, and Chinese medicine practitioners identify symptoms based on the texture, thickness and color of the tongue moss. For example, white moss usually represents cold and deficiency. Yellow moss usually represents heat. Greasy tongue coating usually represents phlegm-dampness and food accumulation (food that is indigested and stagnates in the stomach), while dry coating mostly represents fluid damage.
In addition, the thickness of the tongue coating also reflects the depth of the disease. Thick moss is the main internal evidence, the disease position is deep; thin moss is the main surface evidence, the disease position is shallow. Thick moss becomes thin, mostly suggests that the evil is retreating and the prognosis of the disease is good. Thin moss becomes thicker, suggesting that the disease is progressing and requires extra attention.
If you feel unwell, please consult a doctor in time, do not diagnose on your own to avoid delaying your condition.