Oxygen inhalation is a very common clinical aid, as the name implies, is to let patients inhale oxygen. The main purpose of oxygen inhalation is to improve the hypoxia of the body, and all diseases that cause hypoxia can be used, and its indications are mainly the following: 1, common diseases of the respiratory system: 1, such as chronic obstructive pulmonary disease, namely COPD, bronchial asthma, respiratory failure, respiratory sleep apnea syndrome, etc.; 2, surgery or shock, fetal heart dysplasia, long time coma patients; 3, cardiovascular system related diseases: common are coronary artery disease, angina pectoris, etc.; 4, other diseases that cause hypoxia and lead to chest tightness and shortness of breath. In the respiratory system, for some diseases of respiratory failure, there are various ways of oxygen inhalation, and the common ones are nasal catheter oxygen inhalation, mask oxygen inhalation and oxygen storage mask oxygen inhalation. For the flow rate of oxygen inhalation, patients with type I respiratory failure can take high flow rate oxygen inhalation, while patients with type II respiratory failure generally take low flow rate oxygen inhalation.