Pulse pressure difference of 20mmHg belongs to the normal range, but belongs to the critical value state, the corresponding condition, need to combine with the clinical history and clinical symptoms to make a comprehensive judgment. Pulse pressure difference is the difference between systolic pressure and diastolic pressure, and the normal population is 20-40mmHg. The current result is 20mmHg, which belongs to the normal range, but belongs to the critical value state. It may be accompanied by some physical abnormalities, such as pericardial effusion, accelerated heart rate, and increased peripheral vascular resistance, etc., which need to be further investigated to determine the specific causes before standardized treatment. Pulse pressure difference of 20mmHg and accompanied by obvious physical abnormalities, respiratory restriction and cardiac arrhythmia, need to consult a doctor for observation and standardized treatment under the guidance of a clinician.