Respiratory failure can be divided into acute respiratory failure and chronic respiratory failure according to the onset of the disease, type I respiratory failure and type II respiratory failure according to the presence or absence of carbon dioxide retention, and central respiratory failure and peripheral respiratory failure according to whether or not the respiratory center is involved. 1. The urgency of the onset of the disease: if the onset of the disease is acute, it can be diagnosed as acute respiratory failure; if the onset of the disease is chronic, it can be diagnosed as chronic respiratory failure. 2. Whether it is accompanied by carbon dioxide retention: if the partial pressure of oxygen is less than 60mmHg and PaCO2 is normal or lower, it is type I respiratory failure; if the partial pressure of oxygen is less than 60mmHg and accompanied by carbon dioxide retention (partial pressure of carbon dioxide is more than 45mmHg), it can be diagnosed as type II respiratory failure. 3. Whether the respiratory center is involved, if the respiratory center is involved, it can be diagnosed as central respiratory failure, for example, severe cerebrovascular disease can lead to central respiratory failure; if it is not caused by the respiratory center, it can be diagnosed as peripheral respiratory failure, for example, chronic obstructive pulmonary disease, bronchodilatation, myasthenia gravis, and other diseases, all of which can lead to peripheral respiratory failure. Once diagnosed with respiratory failure, it should be taken seriously, cooperate with the doctor to improve the relevant examination, and standardize the treatment.