Soak the medicine thoroughly before decocting it, soaking it in cold boiling water for about 30 minutes. Add water so that the water level is just above the medicine. Boil the medicine on high heat and then simmer it slowly for about half an hour (about 10 minutes for cold medicine) without removing the lid or stirring frequently to minimize the loss and destruction of volatile components. Generally decoct the drug for 2 times, then mix the 2 decoctions and take it twice in the morning and twice in the evening or 3 times in the morning and in the evening. Choice of water for decocting Chinese medicine: Unless otherwise specified, cool boiled water is generally the best. Cool water can prevent the protein and starch in the cells from coagulation and burnt, while boiling water can avoid the destruction of active ingredients by residual chlorine in tap water and reduce the chance of precipitation of active ingredients combined with calcium and magnesium ions. If conditions do not allow, water can also be used. The choice of decoction apparatus for Chinese medicine: a casserole decoction is preferred because of its uniform heat, gentle heat conduction and stable nature, which is not easy to react with the chemical components contained in the Chinese medicine. In the absence of a casserole, chemically stable tile pots and stainless steel pots can be used instead. Avoid using iron or aluminum pots to avoid precipitation, reduced solubility, or chemical reactions with drugs that may cause toxicity and side effects.