What characteristics does the tongue exhibit in yang deficiency?

In the context of Traditional Chinese Medicine (TCM), a tongue exhibiting characteristics of pale purple with thin to no coat is indicative of yang deficiency. Yang represents warmth and energy, and when there's deficiency, the body tends to show signs of cold and insufficient qi (energy).

A pale tongue suggests a lack of vitality or blood, while a purple color indicates stagnation or a deficiency leading to reduced blood circulation. The presence of a thin to no coating further points to a lack of moisture or nourishment in the body. Together, these characteristics portray a picture consistent with yang deficiency, where the body's warmth and energetic functions are diminished.

This understanding helps practitioners make TCM diagnoses and treatment plans, emphasizing the importance of tongue diagnosis in assessing internal imbalances.