Blood Pressure Measurement

High blood pressure can lead to kidney disease. It can also be a sign that your kidneys are already impaired. The only way to know whether your blood pressure is high is to have a health professional measure it with a blood pressure cuff. The result is expressed as two numbers. The top number, which is called the systolic pressure, represents the pressure when your heart is beating. The bottom number, which is called the diastolic pressure, shows the pressure when your heart is resting between beats. Your blood pressure is considered normal if it stays below 120/80 (expressed as "120 over 80"). The NHLBI recommends that people with kidney disease use whatever therapy is necessary, including lifestyle changes and medicines, to keep their blood pressure below 130/80.

source: http://kidney.niddk.nih.gov/kudiseases/pubs/yourkidneys/index.htm