Blood pressure is the force exerted in the arteries by blood as it circulates.
Normal or healthy BP is regarded as 120/80mmHg or thereabouts.
There are two types of blood pressure:
- Systolic blood pressure refers to the pressure inside your arteries when your heart is pumping;
- Diastolic pressure is the pressure inside your arteries when your heart is resting between beats.
High blood pressure occurs when systolic blood pressure readings consistently exceed 140mmHg and or diastolic readings exceed 90mmHg.
Formula to calculate blood pressure.
BP measurements are usually taken on the upper arm with a sphygmomanometer and a stethoscope.
The sphygmomanometer consists of an inflatable cuff with a pressure gauge.
When inflated, the cuff blocks the flow of blood to the arm below the cuff. As the cuff is allowed to slowly deflate, the equipment listens through the stethoscope to sounds as the artery opens and allows blood flow to continue again.
The first sound heard as the artery opens enough for the first pumps of blood to come through is known as the systolic pressure while the second is the diastolic pressure.
The systolic number is placed over the diastolic number and is always the higher of the two numbers.
Example:
If we can say that your blood pressure is 110/70mmHg. This means that your systolic pressure was 110mmHg while your diastolic pressure is 70mmHg.