Oxygen 88 to 90, usually referred to as oxygen saturation 88%-90%. Oxygen saturation refers to the concentration of oxygen in the blood, which is an important parameter of respiratory circulation. Normally, the normal oxygen saturation should be no less than 95%, and 88%-90% belongs to moderate hypoxia, so patients need to be on oxygen all the time, i.e. to keep a certain time for oxygen therapy every day. Oxygen should be carried out under the guidance of professional doctors, while smoking and other behaviors should be avoided to avoid fire; oxygen saturation should be closely observed when oxygen is administered, if it is stable above 95%, oxygen can be appropriately reduced or stopped according to the patient’s mental state, but if the patient has abnormal symptoms such as poor breathing, he/she needs to be sent to the doctor immediately; if the patient has the need to eat, oxygen can be suspended first. In addition, patients should not change the oxygen concentration and oxygen flow rate without permission to avoid discomfort. In addition to oxygen therapy, patients should also clarify the cause of oxygen deficiency and then carry out targeted treatment. There are many causes of hypoxia, the common ones are chronic obstructive pulmonary disease, pneumonia, bronchial dilatation, heart failure, etc. Taking chronic obstructive pulmonary disease as an example, in addition to continuous, low concentration and low flow oxygen inhalation, patients can be treated with targeted medications under the guidance of professional doctors to relieve symptoms, such as cholinergic receptor blockers, bronchodilators like methylxanthine, or N-acetylcysteine, mucus diluting agents such as carboxymethylstilbestrol.