Solution: Blood pressure is the lateral pressure produced by blood flowing on the blood vessel wall. Blood is mainly produced by the pumping action of the heart. Usually, blood refers to the arterial blood pressure of systemic circulation, which can be measured at the brachial artery of the upper limb. When the heart contracts, the arterial blood pressure is the highest, which is called systolic blood pressure, also called hypertension. When the heart relaxes, the arterial blood pressure is the lowest, which is called diastolic blood pressure or hypotension. The arterial blood pressure of healthy adults is generally maintained at systolic blood pressure 12 ~ 18.7 kPa and diastolic blood pressure 8 ~ 12 kPa. Blood pressure often exceeds 18.7/ 12 kPa, which is called hypertension. Often lower than 12/6.7 kPa, called hypotension. Too high or too low blood pressure is not good for health.
So the answer is: normal systolic blood pressure 12 ~ 18.7 kPa, normal diastolic blood pressure 8 ~ 12 kPa.