What is Yin deficiency? What is Yang deficiency?

Yin deficiency and yang deficiency belong to a description of diseases in traditional Chinese medicine. Yin deficiency refers to the loss of yin qi, resulting in emaciation, dizziness, dry mouth, palpitations, insomnia, thin and frequent pulses, etc. Yang deficiency refers to the loss of yang qi, manifested as fatigue, lack of qi, laziness to speak, fear of cold and cold limbs, pale complexion, light fat tongue, etc.