Air entering the blood vessels during infusion can occur in two ways: dissolved in the blood and air embolism. 1. Dissolved in the blood: If a small amount of air enters the blood vessels, it will return to the right atrium through the veins of the arm and then enter the right ventricle. Due to the small amount of air, it will be pressed into the pulmonary artery by the right ventricle and dispersed into the small pulmonary arteries, and finally the gas will enter the capillaries and dissolve, which will not cause harm to the body. 2. Air embolism: when a large amount of air enters the body, the air mixes with the blood in the right ventricle to form foam. If the mixture enters the pulmonary artery, obstruction occurs, so that the blood can’t enter the lungs, causing death due to severe hypoxia; if the mixture enters the coronary artery, the coronary circulation can be blocked, resulting in cardiac dysfunction and obstruction of blood circulation. It is recommended that patients with the above conditions go to regular hospitals in time, and standardize treatment under the guidance of doctors to avoid delays.