Low blood oxygen refers to the low oxygen content in the blood, resulting in tissue hypoxia in patients, which is also clinically known as hypoxemia, generally oxygen partial pressure below 80 mmHg, is a relatively common type of pathological process, which can affect the brain, heart and other important vital organs hypoxia in serious cases, and can even cause the death of the body. After the body is deprived of oxygen, the cells of tissues and organs are in a hypoxic state, and energy metabolism is impaired. The more common manifestations are cyanosis, fatigue and weakness, rapid breathing and drowsiness, and in the case of acute and severe hypoxia, the organ function will be abnormal, leading to compensatory insufficiency and causing coma. In the case of the circulatory system, for example, there will be an abnormal increase in heart rate, increased contraction of cardiac muscle cells, and increased venous blood return, as well as redistribution of blood flow throughout the body. In addition, the central nervous system is the most sensitive to hypoxia, and irreversible damage can occur when the body is completely hypoxic for 4-6 minutes, causing decreased memory and judgment, uncoordinated limb movements, brain tissue edema, increased intracranial pressure, and neurological dysfunction. Therefore, when the manifestation of low blood oxygen should be improved as soon as possible, oxygen therapy can be given to improve oxygen supply and help correct the abnormal oxygen metabolism.