Fresh rehmannia root can clear away heat and promote fluid production, and after cooling, stop bleeding; It can be used for yin injury caused by hot air, red tongue, polydipsia, macula and rash, hematemesis, epistaxis and sore throat. \x0d\ Rehmannia glutinosa can clear away heat and cool blood, nourish yin and promote fluid production; It can be used for fever, polydipsia, macula and rash, internal heat due to yin deficiency, hematemesis, epistaxis, diabetes and infectious hepatitis. \x0d\ Rehmannia glutinosa polysaccharide can promote the proliferation of bone marrow hematopoietic stem cells in normal mice, stimulate their hematopoietic function, and protect and promote the recovery from radiation injury to some extent. Rehmannia glutinosa oligosaccharide can also enhance hematopoietic stem cells in mice. Rehmannia glutinosa polysaccharide B has obvious immunomodulatory activity and can significantly increase the expression of P53 gene in Lewis liver cancer cells. Thus, the anti-tumor mechanism of Rehmannia glutinosa polysaccharide was found from the gene level. Fresh Rehmannia glutinosa juice, fresh Rehmannia glutinosa juice and dried Rehmannia glutinosa decoction all antagonized the prolongation of coagulation time induced by aspirin in mice, and the effect of fresh Rehmannia glutinosa juice was obviously stronger than that of dried Rehmannia glutinosa juice. The water extract of Rehmannia glutinosa had obvious hypotensive effect and stable blood pressure in cold conditions, which showed that Rehmannia glutinosa has a bidirectional regulation effect on blood pressure. Both raw Rehmannia glutinosa and Rehmannia glutinosa can regulate the thyroid function of hyperthyroidism yin deficiency rat model. In addition, rehmannia glutinosa oligosaccharide can not only regulate experimental diabetes disorder, but also regulate physiological hyperglycemia. Rehmannia glutinosa water extract can also inhibit gastric acid secretion, resist ulcer and have a calming effect. \x0d\ Rehmannia glutinosa is sweet and mild in nature. Liver and kidney meridians entered. Indications: It has the effects of enriching blood and nourishing yin, and can be used for treating blood deficiency, sallow, dizziness, palpitation and insomnia, irregular menstruation, metrorrhagia, etc. It can be used for bone steaming due to kidney yin deficiency, night sweats, nocturnal emission, and thirst quenching, such as Liuwei Dihuang Pill. The effect of replenishing essence and marrow is used for soreness of waist and knees, dizziness and tinnitus, premature graying of hair and beard due to deficiency of liver and kidney essence and blood. \x0d\ Radix Rehmanniae is sweet, bitter and cold. Heart, liver and lung meridians. Indications: It has the efficacy of clearing away heat and cooling blood, and can be used for treating warm diseases with heat entering the blood, strong heat and dizziness, dry mouth and crimson tongue. Such as Qingying soup. In the late stage of treating febrile diseases, the residual heat is not exhausted, the vaginal fluid has been injured, the night is hot and early cold, and the tongue is red and the pulse is rapid, such as Artemisia annua Biejia Decoction. It can be used to treat febrile diseases, such as heat entering the blood, blood heat being toxic, hematemesis and epistaxis, and macula being purple and black. Such as sisheng pills; The effect of nourishing yin and promoting fluid production is used to relieve thirst caused by fluid injury and internal heat. Treating yin injury due to febrile diseases, intestinal dryness and constipation, such as zengye decoction. Decoct10 ~ 30g for medicinal purposes, and double the dosage of fresh products, or use fresh products as medicine. Fresh Radix Rehmanniae tastes bitter and bitter, and has similar effect to dried Radix Rehmanniae, but it has less power of nourishing yin, but it has stronger power of clearing heat, promoting fluid production, cooling blood and stopping bleeding. This product is cold and stagnant, and it is not suitable for people with spleen deficiency and dampness and abdominal fullness in loose stool. Generally, it is not used alone, but generally combined with other Chinese medicines.