Systolic blood pressure occurs when the heart is contracting, and diastolic blood pressure is the pressure generated by the blood on the peripheral arteries when the heart is in diastole. When the heart is contracting, it will pump blood from the left ventricle into the aorta, which will produce lateral pressure on the blood vessel wall, called systolic pressure, and its normal value is usually between 90-140mmHg. Diastolic blood pressure is the pressure of blood in the aorta when the heart is in diastole, and the normal value is between 60-90mmHg. Systolic and diastolic blood pressure are usually put together when describing the normal value of blood pressure. If both systolic and diastolic blood pressure are higher than normal, or if either systolic or diastolic blood pressure is elevated alone, it is considered high blood pressure. The values of systolic and diastolic blood pressure can be used to initially determine the changes in the body’s blood pressure, and it is important to pay attention to a light diet and to avoid emotional stress in order to maintain normal systolic and diastolic blood pressure and to keep the body in good health.