When people eat grains and cereals, it is inevitable that they will have headaches and fever, and naturally, they need to take medicine, including traditional Chinese medicine, western medicine and Chinese medicine. Many people one-sidedly believe that western medicine or Chinese medicine will “hurt the liver and kidneys”. So, how can the drugs that are taken, after entering the body, work as demons? After the drug enters the body as a foreign substance, the body has to mobilize various mechanisms to change the chemical structure of the drug, that is, the transformation of the drug (or biological transformation), also known as drug metabolism, elimination from the body, metabolism is an important way to eliminate drugs in the body. Various tissues in the body have the ability to metabolize drugs to varying degrees, but the liver is the most important drug metabolism organ, in addition, the gastrointestinal tract, lung, skin, kidney, etc. can also produce meaningful drug metabolism. The metabolism of drugs generally decreases or disappears completely, but there are cases where the pharmacological effects or toxicity (including mutagenicity, carcinogenicity and teratogenicity) are increased after metabolism, such as acetaminophen metabolites that have toxic effects on the liver. Therefore, before prescribing drugs to patients, doctors usually ask about liver function and kidney function, in order to prevent drugs from increasing the burden on the liver and kidneys. The liver and kidney function is good or bad, there are many influencing factors, such as hepatitis, nephritis, etc., will have an impact on liver function, kidney function, when the liver cells, kidney cells damage to a certain degree will appear clinical symptoms, the use of many drugs received restrictions. In short, drugs undergo complex physicochemical changes after entering the body. Do not take drugs casually, and do not dare to take drugs. It is recommended to take drugs under the guidance of doctors in regular hospitals to reduce the adverse effects of drugs.