Symptoms of tongue coating due to yin deficiency and yang deficiency

Tongue coating of yin deficiency is mostly red tongue with few cracks and lack of fluid. Tongue coating of yang deficiency is light fat tongue with tooth marks, white coating and hydrotalciousness. This is tongue coating under normal circumstances. However, the actual situation is complicated. TCM stresses four diagnostic methods, that is, a diagnosis cannot be made by a certain diagnostic method alone. It must be combined with inspection, hearing, inquiry and palpation to make a comprehensive judgment. Tongue coating inspection is an important aspect of inspection. Traditional Chinese medicine believes that tongue substance reflects qi and blood conditions of the body, and tongue coating reflects the ups and downs of evil factors.