Blood pressure is divided into systolic and diastolic, and the difference between systolic and diastolic pressure is called the “pulse pressure difference”. For example, if the systolic pressure is 120 mmHg and the diastolic pressure is 75 mmHg, the pulse pressure difference is 45 mmHg. In general, the normal human pulse pressure difference of 20-60 mm Hg (2.67-8.0 Kpa), greater than 60 mm Hg for the pulse pressure difference is too large, less than 20 mm Hg is too small. Commonly small pulse pressure difference is mostly caused by a decrease in systolic pressure (high pressure), of which there are physiological factors and pathological causes. Of the former systolic blood pressure decline is mostly seen in the body wasting or weak, the latter category is seen in shock, myocardial infarction, cardiac insufficiency, pericardial tamponade, hyperalgesia and other diseases. Other organic pathologies that may cause a decrease in pulse pressure difference include pericardial effusion, constrictive pericarditis, severe mitral stenosis, and aortic stenosis. Therefore, when the pulse pressure difference is found to be significantly reduced, various organic lesions should be excluded first, such as after detailed examination, if no clear cause is found, it should be considered to belong to the somatic blood pressure reduction (mainly refers to systolic blood pressure), treatment of somatic hypotension, in addition to strengthening physical strength, proper nutrition, but also to prevent dizziness when upright, or fall. Drugs can be used to regulate the role of plant nerve function, such as glutamate, vitamins. It is not necessary to pay too much attention to the phenomenon of small pulse pressure difference without discomfort, because it will not have too much impact on health.