Blood pressure results from two forces.
One is created by the heart as it pumps blood into the arteries and through the circulatory system. The other is the force of the arteries as they resist the blood flow. The systolic pressure is always stated first and the diastolic pressure second. Blood pressure of less than 140 over 90 is considered a normal reading for adults. A systolic pressure of 130 to 139 or a diastolic pressure of 85 to 89 needs to be watched carefully.