Er Miao San is consumed as a decoction of water, or made into pills or powder for administration. Ermiao San is composed of Huangbai and Cangzhu, with the efficacy of clearing heat and drying dampness (removing heat and drying dampness), it is used for the treatment of dampness-heat injection (dampness and heat invading the intestines, bladder, pubic area, lower limbs, etc.), which is indicated by pain in the tendons and bones, impotence of the two feet, redness, swelling and pain in the feet and knees, dampness-heat subluxation, dampness-heat sores in the lower part of the body, and short and reddish urination (small amount of urination, dark yellow color). In the formula, Huang Bai is cold, bitter and dry, its nature is subdued, and it is good at clearing dampness-heat in the lower Jiao (dampness and heat evils invading the intestines, bladder, pubic area, lower limbs, etc.); Cangzhu is hard and warm, and its nature is dry and intense, which can strengthen the spleen and help transporting and removing dampness. The adverse reactions and contraindications of Ermiao San are not clear. If you need to use the drug, you should be guided by a traditional Chinese medicine practitioner under the guidance of the identification of the drug, do not buy your own medicine to use, so as to avoid delaying the condition of the drug is not the right evidence.