The main reason for low blood pressure and high blood pressure is a decrease in the elasticity of blood vessels, which causes the blood to exert pressure on the walls of the blood vessels, generating too high a pressure during systole and too low a pressure during diastole, resulting in an increase in the difference in pulse pressure. Mainly seen in. 1. Simple hypertension in the elderly: with gradual increase in age, the aorta and large arteries harden, resulting in decreased elasticity of blood vessels, which cannot expand to accommodate more blood during systole, leading to increased systolic blood pressure. During diastole, the elasticity of blood vessels is weakened and the blood flow into the periphery is also reduced, resulting in lower diastolic blood pressure. 2. Severe anemia, hyperthyroidism and other high power circulatory state: when suffering from severe anemia and hyperthyroidism, due to the patient’s body’s metabolic function is more hyperactive, and the system’s excitability is obviously increased, which can cause the pulse pressure difference to increase. 3. In addition, arteriosclerosis, rheumatic heart disease, aortic insufficiency, some congenital heart disease, bacterial endocarditis, etc., can cause low pressure and high pressure, pulse pressure difference increases. When the blood pressure manifests itself in this kind of situation, it is recommended to go to the hospital for a detailed examination to clarify the cause of the disease and then carry out targeted treatment.