What do the systolic and diastolic blood pressure numbers mean? When you get a blood pressure number, there are two of them. The first, or "top," is the systolic pressure. The second, the lower, is the diastolic pressure. Knowing both is important and can save your life. What does the systolic pressure value mean? When the heart beats, it compresses and pushes blood through the arteries to the rest of the body. This force puts pressure on the blood vessels and this is the systolic pressure. Here's how to understand the value of systolic blood pressure: Normal: Less than 120 Increased: 120-129 Stage 1 high blood pressure (also called hypertension): 130-139 Stage 2 hypertension: 140 or more Hypertensive crisis: 180 or more. Call 911. What does the diastolic blood pressure number mean? Diastolic pressure, or the lower number, is the pressure in the arteries when the heart is resting between beats. This is the time when the heart fills with blood and receives oxygen. Here's what the diastolic blood pressure number means: Normal: Less than 80 Grade 1 hypertension: 80-89 Grade 2 hypertension: 90 or more Hypertensive crisis: 120 or more. Call 911. Which is more important systolic or diastolic? Over the years, studies have shown that both numbers are equally important in monitoring heart health. However, most studies show a higher risk of stroke and heart disease associated with higher systolic blood pressure compared to elevated diastolic blood pressure. When is the best time to measure blood pressure? They should be measured in the morning, before eating or taking any medications. Then repeat them in the evening. Take two or three readings at each measurement to make sure the results are the same. Your doctor may recommend that you measure your blood pressure at the same time each day. Should I be concerned if my diastolic blood pressure is high? Unless you have other health problems that increase your risk of cardiovascular problems, the situation you describe - isolated diastolic hypertension - is not dangerous now. But it is also not normal. People with elevated diastolic pressure often develop elevated systolic pressure over time. Which is more important systolic or diastolic? While both numbers in a blood pressure reading are important for diagnosing and treating high blood pressure, doctors focus primarily on the highest number, also known as systolic blood pressure. Systolic pressure reflects the force with which the heart pumps blood into the body, while diastolic pressure (the lower number) is the pressure in the blood vessels when the heart is at rest.