“Exudation and extravasation” refers to the adverse effects of drugs entering the surrounding tissues, which can result in localized inflammatory reactions or even necrosis. The main risk factors include: drug factors, medical technology factors, patient factors, disease factors and so on. 1. Drug factors: the drug can make the normal metabolism and function of the endothelium affected, causing inflammatory reaction and increased vascular permeability, leading to extravasation of the drug. 2. Medical factors: such as improper selection of blood vessels during venipuncture, poor puncture technique, failure to inspect the venous channel and puncture site in a timely manner, and failure to find out when the fixed dressing falls off. 3. Patient factors: the patient’s crying, skin relaxation, increased brittleness of venous blood vessels can easily lead to needle displacement and extravasation. 4. Disease factors: the patient’s vascular relaxation and contraction status, permeability, vascular sclerosis, etc. are all related to drug extravasation. If there is drug “leakage and extravasation” should promptly inform the doctor and nurse, immediately remove the infusion line, and take appropriate measures to reduce the adverse consequences.