Low blood is defined as Blood deficiency. Kidney yang deficiency does not usually lead to blood deficiency, but kidney yin deficiency can lead to blood deficiency. Kidney yang deficiency is caused by factor body yang deficiency or prolonged illness, excessive loss, and weakness in old age, which can lead to cold form (cold body), cold limbs, lack of mental energy, shortness of breath and wheezing, lumbar and knee soreness and weakness (feeling of soreness and weakness in lumbar and knee), impotence, slippery semen, and nighttime urination and other conditions. According to traditional Chinese medicine, essence can transform blood, blood can nourish essence, and the relationship between essence and blood has mutual nourishment and mutual transformation, called “essence and blood of the same origin”. The essence of water and grains and kidney essence are the basic substances for blood production, in which the kidneys store the essence, and the essence is the source of blood production, and the loss of kidney essence can show signs of blood deficiency, as well as common hair withering and shedding symptoms. The patient should consult a doctor in a timely manner and choose medication under the guidance of a physician to avoid delaying the condition.