When the concentration of carbon dioxide is low, it is generally not toxic to the human body, and the air we breathe every day contains a certain amount of carbon dioxide. However, if you are in a relatively low concentration of carbon dioxide for a long period of time, and more than the safe concentration of carbon dioxide, or suddenly enter into a high concentration of carbon dioxide environment, it may lead to carbon dioxide poisoning of the body. In addition, there are also some people who have abnormalities such as ventilation dysfunction, which can cause a series of uncomfortable symptoms and toxic effects due to carbon dioxide retention in the body.1. Normal inhalation of carbon dioxide: normal inhalation of carbon dioxide in the body can regulate respiration and stimulate the nerves to carry out normal respiratory effects. Normal inhalation of carbon dioxide diffusion into the blood can be converted into carbonic acid, which is conducive to maintaining the acid-base balance of the body. Inhaled normal amount of carbon dioxide can also maintain the oxygen supply balance of the body in the respiratory process; 2, carbon dioxide poisoning: inhalation of high concentration of carbon dioxide in the body, the stimulation of carbon dioxide on the medulla oblongata changes from promotion to inhibition. It may cause the body to be hypoxic or lead to central nerve paralysis, causing acute carbon dioxide poisoning. In turn, dizziness, palpitations, coma, etc. occur. If you do not leave the high concentration of carbon dioxide environment in time, you may aggravate the poisoning reaction, vomiting, limb stiffness and other manifestations, and in serious cases, it may cause respiratory and circulatory failure, threatening life and health; 3, carbon dioxide retention: due to some respiratory system diseases, such as pulmonary edema, pulmonary fibrosis, etc. lead to the phenomenon of carbon dioxide retention in the body, resulting in high carbon dioxide content in the body, the body is hypoxic, respiratory distress The symptoms of carbon dioxide retention are: high carbon dioxide level in the body, lack of oxygen, difficulty in breathing, coma, headache, etc., which may cause respiratory failure in serious cases.