Several factors affecting blood pressure, including the following five aspects: First, the first heart per-pulse output, per-pulse output mainly affects systolic blood pressure, with the increase of per-pulse output, systolic blood pressure echo is high, so it is the determining factor affecting systolic blood pressure. Second, peripheral vascular resistance, peripheral vascular resistance to diastolic blood pressure is more obvious, peripheral vascular resistance is large, the higher the diastolic blood pressure. Third, the elasticity of the large arteries, in the arterial elasticity decline, brittleness enhancement, will lead to a rise in blood pressure, mainly in systolic blood pressure increase, but also cause the increase of diastolic blood pressure. Fourth, heart rate, usually, when the human heart rate increases, the diastolic blood pressure will rise, the systolic blood pressure will also increase, but with the increase of diastolic blood pressure. Fifth, effective circulating blood volume, for example, patients appear due to shock and other factors lead to effective circulating blood volume is insufficient, will cause blood pressure drop.