Blood or arterial pressure is essential for proper provision of the body organs with oxygen and nutrients. Normal blood pressure is a sign of good health of the body, whereas high or low blood pressure may indicate certain disorders.
As you know, the blood in our body moves in vessels: veins, capillaries, and arteries. When moving, it puts pressure on the vessel walls. The types of the blood pressure include intracardial, capillary, venous, and arterial.
The arterial pressure is the most important for diagnoses. Therefore, when we speak about blood pressure, we normally mean the arterial pressure.
The pressure is created in large arteries as a result of the heart contractile activity. It provides for sufficient blood circulation and delivery of nutrients and oxygen to body organs and tissues.
As a rule, the artery pressure readings are made up of two numbers. The first one goes for systolic artery pressure. Its index shows the pressure at the moment of the heart contraction. This is the highest point of the blood pressure, also known as the upper pressure. The diastolic, or lower, blood pressure is enclosed in the second number, and shows the blood pressure when the heart muscle is relaxed.
For arterial pressure measurement millimeters of mercury (mm Hg) are used. Thus, a reading 120/80 mm Hg means that the level of the systolic blood pressure is 120 mm Hg, and the diastolic pressure is 80 mm Hg. For many people, 120/80 mm Hg (or close to it) is considered to be a norm. However, for each person the norm can vary. Several factors have to be taken into account when measuring the blood pressure.
The pressure readings can differ depending on the situation. Thus, it increases during activity or stress, and decreases in calm conditions and during sleep. For different age groups the blood pressure norms are different too. As a rule, in the childhood it is relatively low, but still considered to be the norm. With times, the norm of the blood pressure goes up. For this reason, elderly people quite often experience symptoms of hypertension. There can be temporary pressure fluctuations during hormonal changes in the body, for example, during puberty period, or pregnancy.