Carbon monoxide can cause tissue hypoxia when inhaled. Carbon monoxide is a colorless and odorless gas, and the main component of gas is carbon monoxide. The pungent odor of a gas leak is an artificially added irritant gas to alert people, not the odor of carbon monoxide. After carbon monoxide is inhaled by the body, it competes with oxygen for hemoglobin because its affinity for hemoglobin is hundreds of times higher than that of oxygen. Once the hemoglobin is combined with carbon monoxide, it loses the ability to combine with oxygen, thus not being able to transport oxygen to various tissues and organs in the body, which can cause tissue hypoxia, especially in the brain, a tissue with high oxygen consumption, where hypoxia can cause impaired function, which gradually worsens with the prolongation of hypoxia, and brain cells can become edematous and necrotic or even brain dead due to hypoxia. Other organs of the body will also cause dysfunction due to lack of oxygen, so carbon monoxide has a great danger to the human body.