You are certainly no stranger to the term blood pressure, but how many types of blood pressure are there? What is it all about? What is the impact of blood pressure on our lives and health? What are the dangers associated with a sustained increase in blood pressure? These questions may not be well understood by many people. Blood pressure (BP) is the lateral pressure that blood exerts on the walls of the arteries during the flow of blood. Although BP is called “pressure”, it is actually “pressure”, which means the pressure per unit area of the arterial blood vessel wall. In other words, when we measure blood pressure, we are measuring the arterial blood pressure at the limb where the sphygmomanometer is placed. From this, we then deduce the total blood pressure of the person being measured. The first observational study of blood pressure was conducted by Stephen Hales, an English priest, as early as 1733, when he first connected a copper tube to a glass tube perpendicular to the ground and then inserted the tube into a horse’s artery, initially determining the horse’s blood pressure by observing the height of the blood column in the glass tube. 1854 saw Vierordt design the first arterial sphygmomanometer, and 1896 saw the Italian Dr. Rive was the first to use the mercury column cuff sphygmomanometer in a clinical setting, and in 1905 Dr. Korotkoff in Russia recommended the use of a stethoscope to measure blood pressure. Since then, through years of intensive research, physicians have developed a deeper and more refined understanding of the formation of blood pressure, the factors that influence it, and a host of other related issues, which have become the theoretical basis for modern medicine surrounding the diagnosis, treatment, and prevention of blood pressure-related conditions. Blood pressure is an important foundation for the formation of life and even the maintenance of life, and is an important vital sign for us. Without blood pressure, blood would not flow forward and the organs of the body would not be supplied with blood. So how is blood pressure formed? It starts with a complete, airtight tube with a constant flow of blood, which is our blood circulation system. In this system, the heart works week in and week out, sending a constant flow of blood into the arterial vessels when the heart contracts, and a constant flow of blood from the veins back to the heart when the heart diastolic, thus creating a blood circulation, so the heartbeat is the power source of blood pressure. In the forward flow of blood will certainly encounter resistance, these resistance mainly from the walls of the blood vessels, in the power and resistance interaction, the formation of our blood pressure. In most cases the softer the blood vessel, the more elastic it is, the less resistance, and conversely the harder the blood vessel, the greater the resistance. This is why blood pressure is usually higher in people with atherosclerosis. The blood pressure measured when the heart is systolic is called the systolic pressure, or commonly known as “high pressure”, and the blood pressure when the heart is diastolic is called the diastolic pressure, or commonly known as “low pressure”. Blood pressure is expressed in kilopascals (kPa) or millimeters of mercury (mmHg), which is converted to 1 kPa equals 7.5 mmHg and 1 mmHg equals 0.133 kPa. According to the Supplementary Notice on the Use of Blood Pressure Measurement Units jointly issued by the State Bureau of Quality and Technical Supervision and the Ministry of Health in China, millimeters of mercury (mmHg) is now mostly used as the unit of measurement for blood pressure. In medicine, blood pressure can be divided into two types: ambulatory blood pressure, which is also known as instantaneous blood pressure, which is the data obtained when blood pressure is measured at any time, so in most cases we refer to blood pressure as ambulatory blood pressure. The former, also known as instantaneous blood pressure, is obtained when blood pressure is measured at any time. The latter is a blood pressure monitoring tool that has been widely used in clinical practice until recently. It represents the patient’s blood pressure over a period of time (usually 24 hours) and can reflect the blood pressure of the subject and the fluctuations over time with relative accuracy.