Let me see if this helps you:
Blood pressure is the amount of force (pressure) that blood exerts on the walls of the blood vessels as it passes through them. There are two pressures measured for blood pressure:
- Pressure while the heart is beating (known as systolic blood pressure)
- Pressure while it is relaxed (known as diastolic blood pressure).
Diastolic blood pressure changes frequently throughout the day. Things that can make diastolic blood pressure change within a few minutes include:
- Level of exercise
- Amount of tension
- Nicotine use.
Therefore, it's best to use several blood pressure readings to arrive at your average blood pressure.
Be sure to look at your overall health, lifestyle, diet, and family history when comparing your blood pressure to what's considered "normal blood pressure." These factors may cause you to have a higher or lower blood pressure than what's considered normal. Reference: eMed
I wish I knew a simple answer but I don't so the above is the best I can do.