Yang deficiency means that there is insufficient yang energy in the body, leading to reduced function, decreased immunity, and slow metabolism, presenting a state of yang heat deficiency. In contrast, yin deficiency is a lack of body fluids, unable to nourish the body sufficiently, losing the balance constraint of yang energy, and triggering a series of pathological changes.
The key to distinguishing between yang deficiency and yin deficiency lies in observing individual symptoms. Those with yang deficiency are usually sensitive to cold, with cold limbs; while those with yin deficiency tend to be sensitive to heat, accompanied by rising deficient fire, feeling restless and agitated. Yang deficiency constitution may also lead to poor digestion, with undigested food being excreted, accompanied by mental fatigue and physical weakness. In comparison, people with a yin deficiency constitution have relatively vigorous energy, are active and easily excited, but slightly lack self-control.
From the tongue examination, the tongue of those with yang deficiency is pale in color, may be swollen with tooth marks, and the pulse is deep, thin, and weak; while those with yin deficiency have a red and moist tongue, less tongue coating, and although the pulse is weak, it is different from yang deficiency.
For yang deficiency, it can be improved through dietary supplementation, recommending the consumption of lamb, milk, goose meat, shrimp, eel, chives, garlic, coix seed, Chinese yam, and red dates as warm-tonifying foods. As for yin deficiency, it is necessary to choose heat-clearing foods, avoid spicy, heavily fragrant, and strongly dispersing foods to prevent exacerbating the condition of internal heat.
