The blood pressure chart is straightforward. All you have to do is find your systolic and diastolic numbers. The systolic number is found on the left side of the chart. Meanwhile, the diastolic number is located at the bottom. The two lines where they intersect is the blood pressure reading. The chart also indicates whether the blood pressure reading is low, average, hypertension, or a hypertensive crisis. Most of these charts are color-coded, so it is easy to determine the reading category.