Symptoms of yin deficiency of the heart and kidneys (deficiency of yin fluid in the heart and kidneys) can be seen in insomnia, heartburn, and lumbar and knee soreness (a feeling of soreness and weakness in the lumbar and knee regions). The causes are mostly long illnesses and heat illnesses that deplete yin fluid. Common symptoms of Yin deficiency of the Heart and Kidneys include restlessness and insomnia, palpitations (rapid heartbeat, often accompanied by panic), dryness of the mouth and tongue, dizziness and tinnitus, and heat in the hands and feet, as well as spermatorrhea in men, and menstrual irregularities in women. The causes of yin deficiency of the heart and kidney include prolonged illness and labor injury, depletion of yin; it may also be a result of prolonged thinking, emotional upset, depression and fire, which burns the fluids and damages the yin; and over-eating spicy and stimulating things, which damages the yin, and so on. Commonly used prescription drugs for treating yin deficiency of heart and kidney include Tianwang Xinxin Tonic Dan, which is composed of cypress seed kernel, maitong, asparagus, shengdi, angelica sinensis, danshen, xuanshen, ginseng, platycodon grandiflorus, cinnabar, farnesol, poria, schizandra, and other medicines. It has the function of nourishing blood and tonifying the heart, nourishing yin and clearing heat (nourishing yin essence and clearing heat). Adverse effects are not clear. It is not recommended for people with deficiency of spleen and stomach (spleen and stomach weak and cold) and phlegm-dampness. If there is any discomfort, it is recommended to consult a doctor promptly and use the medicine under the supervision of a physician.