Blood pressure is the energy and strength that is pressing on the walls of the arteries. When measuring it, two numbers are being used to identify blood pressure namely systolic and diastolic pressure. Systolic pressure is represented by the top number and measures the particular contraction and heart beat, while the bottom number seen measures the heart relax or that something between the beats. Usually, a 120/80 blood pressure is considered perfectly normal. Systolic is 120 and diastolic is 80. But then, in order to be accurate, you need to check it several times in a day in order to identify your perfect blood pressure.