Blood pressure is one of the most important characteristics of a cardiovascular system. It is a build-up of fluid pressure that is exerted on the blood vessels by the continuous flow of blood. Blood pressure is considered one of the essential vital body signs, helping a physician to determine health of a patient.
What is Blood Pressure?
Blood pressure is regulated by the body, and can depend on activity levels, lifestyle factors and genetic origins. Blood pressure is measured in the units of mm Hg. There are two components for blood pressure levels, the maximum pressure (systolic) and the minimum pressure (diastolic).
Normal blood pressure is when the range is around 120 per systolic and 80 per diastolic. When the levels of blood pressure are higher than this, the condition is known as hypertension, and hypotension in the levels are lower.
Mechanism of Action
Blood pressure is generated by the beating of the heart. Every time heart pumps out blood, and fills itself back up again, it creates a fluid difference. This fluid difference helps the blood to go from one place to another. In simpler words, the heart needs to push blood with enough force that it reaches the tip of your thumb and toes. This force or pressure regulates the uniform distribution of blood. Normal blood pressure is dependent on a lot of factors. These factors include:
- The amount of blood in the body – the more blood, the higher the blood pressure would be. Anaemic people often have lower blood pressure ranges for this reason.
- Vascular resistance – The resistance offered by blood vessels is dependent on the length of the blood vessel, blood thickness and vessel radius. The higher the resistance, the higher the pressure.
- Blood viscosity – Thickness of the blood is responsible for higher blood pressures. For example, in anaemia, there are not enough red blood cells in the blood, which can change the thickness of the blood. Similarly, unhealthy clotting blood also increases thickness and viscosity increasing blood pressure.
- Hormones called baroreceptors are responsible for regulating the blood pressure levels in the body. Any form of irregularity in these hormones can cause a change in blood pressure.
What do Different Values of Blood Pressure Mean?
The normal blood pressure range is a global standard that is followed by physicians all over the world. If your blood pressure falls in the normal range, you are generally considered as having a healthy cardiovascular system. If your blood pressure varies and lies above the normal range, you are considered to have high blood pressure, and if your blood pressure lies below the range, you are considered to have a low blood pressure.
What are Ranges for Normal Blood Pressure?
The normal range of systolic values for adults should be between 90 and 119mmHg and between 60 to 79mmHg for diastolic values. The normal range of blood pressure for infants is 75-100mmHg systolic and 50-70mmHg diastolic. For toddlers aged 1 to 5 years, the range is 80-110mmHg systolic and 50-80mmHg diastolic. For children aged 6 to 12 years, the range is 85-120mmHg systolic and 50-80mmHg diastolic, and for teenagers, the range is 95-140mmHg systolic and 60-90mmHg diastolic.
How Do You Measure Blood Pressure?
The most common method for measuring blood pressure is through a sphygmomanometer. A pad is applied on the arm tightly, and then the pad is filled with air. Using a stethoscope, the blood pressure reader listens for the first beat when lowering pressure, and then the reader keeps lowering the air pressure until no sound can be heard. These two values are recorded as a blood pressure range. Sphygmomanometers have now been replaced with electronic blood pressure meters which allow a person to measure their blood pressure on their own.