What do the numbers mean?
Just as your age is measured in years and length in meters, blood pressure is measured in millimeters of mercury (mmHg).
Your blood pressure is recorded as two numbers.
For example, 140/90 mm Hg, which is read as 140 over 90.
- The top (first) number, is the systolic pressure. This is the pressure in your arteries when your heart contracts.
- The bottom (second) number, is the diastolic pressure. This is the pressure in your arteries when your heart relaxes between each heartbeat.
What is a high reading?
Your blood pressure is high when your systolic pressure is greater than 140 mmHg or your diastolic pressure is greater than 90 mmHg. With that said, either your diastolic or systolic pressure can be elevated on its own.
- High systolic pressure alone – for example, 170/70 mm Hg.
- High diastolic pressure alone – for example, 120/104 mm Hg.
- Or both can be raised – for example, 170/110 mm Hg.
If your blood pressure recurrently, (more than once), has a systolic pressure of greater than 140 or a diastolic pressure of greater than 90 mm Hg, then you are diagnosed as having Hypertension.
For persons who are diabetic or who have kidney disease, they are diagnosed as hypertensive if the blood pressure is greater than 130/85 mmHg.
Table of the ranges of blood pressures and their respective meanings for an adult