Biological agents are not harmful when used in a normal and standardized manner, but there are adverse reactions. The adverse reactions of different types of biological agents are different, mainly including respiratory symptoms, bone marrow suppression, body discomfort, digestive system adverse reactions, local skin irritation and so on. 1. Tumor necrosis factor inhibitors: cough, fever, generalized muscle pain, upper respiratory tract infection symptoms. 2. Anti-CD-20 monoclonal antibody: Bone marrow suppression may occur, leading to neutropenia, leukopenia, platelet count reduction, etc. In addition, there are nausea and vomiting, impaired liver function. 3. Interleukin-1 blocker: it can cause weakness, local skin redness and itching, flu-like symptoms. The above are only some of the common adverse reactions of biological agents. If there are suspected adverse reactions, stop using the drug immediately and seek medical help as soon as possible. The use of biological drugs must follow the doctor’s instructions, not blindly use their own medicine, so as not to cause adverse effects.