Dihuang is divided into raw dihuang and ripened dihuang, raw dihuang may have diarrhea, abdominal pain and other adverse reactions in a few patients, dampness in the spleen and stomach and yang deficiency, phlegm in the chest and diaphragm should not be taken. The side effects of Radix Rehmanniae Praeparata are not clear, and it is not recommended for those with weak spleen and stomach, stagnant qi and phlegm, and fullness of the abdomen and loose stools (thinning of the feces). 1. Raw dihuang is sweet and cold. It has the efficacy of nourishing yin and generating fluids (nourishing the body’s yin fluid and replenishing the body’s moisture), clearing heat and cooling the blood (relieving blood heat by clearing heat), and is mainly used in the treatment of warm poisonous spots (spots and plaques on the skin caused by warm poisonous evils that invade the human body), vomiting of blood, nosebleed, fluid injury and thirst, constipation, and yin deficiency with fever, and other conditions. A few patients may have adverse reactions such as diarrhea, abdominal pain, dizziness, fatigue, palpitation (rapid heartbeat, often accompanied by panic) after taking the medicine, which may disappear on their own within a few days. It is not recommended for those who have dampness in the spleen and stomach, or those who have Yang deficiency or phlegm in the chest and diaphragm. 2. Radix Rehmanniae Praeparata, sweet, slightly warm. It can replenish blood and nourish yin, benefit essence and fill in marrow. It is used for palpitations (rapid heartbeat, often accompanied by panic) and palpitation (rapid heartbeat, panic) caused by blood deficiency, irregular menstruation, lumbar and knee soreness (a feeling of soreness and weakness in the lumbar and knees), hot flashes (a burst of hotness), vertigo, and ringing in the ears due to deficiency of yin in the liver and kidney (insufficient yin in the liver and kidneys). The side effects of Radix Rehmanniae are not known. It is contraindicated for weak spleen and stomach, stagnant qi and phlegm, and fullness in the abdomen and loose stools (thin and unformed feces). The above medicines are recommended to be used under medical supervision and should not be taken by oneself.