Nowadays, many people think that herbal medicine is a cure for illnesses and a health enhancer for non-illnesses. In fact, as the ancients say: medicine is poison. Medicine is not divided into Chinese and Western, use the right, save life; use the wrong, hurt life. The variety of Chinese medicine, the same name or different drugs and similar morphology of many plants, so that some toxic herbs are misused as non-toxic herbs. Overdose is an important cause of kidney damage caused by herbal medicines. For example, according to the Dictionary of Chinese Medicine, the dosage is within 6 grams, and the dosage of motherwort is 15 to 30 grams, but there have been many clinical reports of kidney function damage caused by overdose of mucuna pruriens and motherwort. There are also cases of overdose poisoning because a certain type of Chinese medicine is itself poisonous. For example, inappropriate use of Leigongteng can cause poisoning. Some Chinese medicines are not used in large doses, but continuous use can also lead to accumulation of poisoning, resulting in kidney damage. There is information from abroad that long-term use of weight loss Chinese medicine containing Fangqi and Houpao can cause chronic interstitial nephritis. Chinese medicines containing metal and ore components in the body but x extremely slow, long-term use can also cause kidney damage. Chinese herbal drinks have to be decocted and drunk, and many patients think that boiling is good. In fact, the decoction method is different for different medicines. The incorrect time and method of decoction can also cause poisoning. Chinese herbs such as Chuan Wu and Cao Wu need to be decocted for more than 15 minutes before other drugs can be added to the decoction, so if the decoction time is not enough, it is easy to be poisoned after taking. On the contrary, the longer the decoction time, the stronger the toxic side effects. In addition, individual differences, allergies are also one of the causes of liver and kidney damage, each person’s reaction to drugs is different, some drug doses for the general use of people do not F toxicity, but allergic people may cause poisoning; weak people to poor tolerance of drugs, taking normal doses also have side effects. Therefore, before patients take herbal medicines, it is better to find a doctor’s prescription and identify the evidence to treat.