Describe the characteristics of "Yang Deficiency" in TCM.

Yang Deficiency in Traditional Chinese Medicine (TCM) is characterized by a lack of warm, active energy within the body. Key signs include cold extremities, which arise due to insufficient Yang energy to warm the body, leading to a feeling of chilliness, particularly in the hands and feet. Fatigue is also prevalent as Yang energy governs activity and vitality; without it, patients often experience significant tiredness and lack of motivation. A pale tongue with a white coating reflects a deficiency state, suggesting that the Qi and blood may be lacking in warmth and nourishment.

The other options reflect conditions that align more with excess Yang or heat. For instance, sensations of heat and excessive perspiration typically indicate an overabundance of Yang energy rather than a deficiency. Jitteriness and dryness point more towards an imbalance associated with dryness and heat conditions, which is a different pathological process. Finally, while sweating and dizziness can occasionally overlap with Yang Deficiency, the description does not as distinctly pertain to the fundamental nature of Yang Deficiency, particularly with regard to tongue characteristics, which are not clearly described here.

Thus, option A accurately captures the essence of Yang Deficiency by highlighting the key symptoms: cold extremities, fatigue, and the specific appearance of the