Dried dihuang is raw dihuang. Dried Dihuang, also known as Raw Dihuang, belongs to the heat-clearing and blood-cooling medicines in the heat-clearing medicines, and is the tuberous root of Dihuang, a plant of the family Xuanxianaceae. Dried Dihuang is sweet, bitter and cold in nature. It enters the heart meridian, liver meridian and kidney meridian. The dosage is 10~15 g. Dried Radix Rehmanniae is effective in clearing heat and cooling blood, nourishing yin and promoting the production of body fluid, and is mainly used in the treatment of heat entering the camp and blood (the degree of invasion of heat into the human body is deep and the symptoms are more serious), fever and spotting of warm diseases, fever and thirst, internal heat and thirst (internal heat accompanied by symptoms such as excessive food, drinking and urination), bone vapor and labor heat, blood heat caused by blood, such as vomiting and bleeding, blood in stools and stools, leakage of menstruation, urinating and blood, and constipation caused by injury of body fluid. Dried Radix Rehmanniae is not suitable for those with spleen deficiency, dampness stagnation, abdominal fullness and loose stools (thin and unformed feces). The adverse effects of Dried Radix Rehmanniae are not known. If necessary, please use it under the guidance of a professional Chinese medicine practitioner.