Most infusions are administered intravenously to help the body treat diseases and restore health when medication cannot effectively treat the disease. Usually, infusions are performed in regular hospitals or clinics and operated by professional medical personnel, and generally do not cause any harm to human body. However, due to long infusion time, contamination of utensils, improper operation and other factors, it may cause some hazards, the common ones include fever, increased circulatory load, phlebitis, air embolism, etc. 1. fever: it is often related to improper cleaning of infusion utensils, poor preservation of drugs, failure to follow aseptic operation and other factors that cause bacterial infection during infusion, or input of thermogenic substances, mainly manifesting as fear of cold, chills, fever. The main manifestations are fear of cold, chills, fever, temperature rise mostly at 38-40℃, and headache, vomiting, nausea and other symptoms may appear in patients with high fever; 2. Increased circulatory load: frequent infusion or too fast infusion speed may lead to excessive circulatory load, water and sodium retention, and pulmonary edema. This tendency may be aggravated if the patient is a patient with kidney disease. The clinical manifestations are mainly dyspnea, chest tightness, coughing, and pink foamy sputum; 3. Phlebitis: long-term input of highly concentrated and stimulating medication, or prolonged retention of indwelling needles in the body, or failure to operate strictly aseptically, may lead to inflammatory reactions in the local venous blood vessel walls. It can be seen as red lines along the vein, often accompanied by local redness, swelling, pain, fever, chill and other symptoms; 4. Air embolism: It is often related to the air in the infusion catheter is not exhausted, the catheter connection is not tight, the puncture point is not sealed tightly, and the infusion is completed without timely replacement of drugs or needle removal, etc. The patient may experience chest discomfort or pain behind the chest, followed by dyspnea, severe cyanosis and other symptoms. General physician auscultation can hear loud and continuous blistering sound; 5. Other hazards: including skin breakage, infusion particle contamination, disease resistance, drug allergy, etc., but after active intervention and treatment, it often does not cause serious hazards, and patients can not worry too much. Some drugs such as azithromycin and other highly irritating drugs may stimulate blood vessels to produce pain and gastrointestinal symptoms, which can be relieved after stopping the injection. Patients are advised to try to have their infusions in a hospital or clinic to facilitate timely intervention if adverse reactions occur during the infusion process. Infusion, fluid exchange and needle removal operations should also be performed under the operation of medical professionals to avoid damage to the patient’s organism caused by improper operation.