What's a Normal Blood Pressure?

A wealth of information is available about blood pressure, and sometimes the most important points get lost or confused. Although we often hear announcements in the press about new or revised blood-pressure guidelines, the basic facts haven't really changed much over the past several decades.
Blood pressure is measured by two numbers. The systolic pressure (the "top" number) is the highest pressure inside your arteries, measured at the moment when your heart is contracting.
It's the active part of a heartbeat. In contrast, the diastolic pressure (the "bottom" number) is the lowest pressure in your arteries, measured while your heart is relaxing between beats.
Experts have long debated whether the systolic or diastolic pressure is more important for health. The current evidence suggests that the systolic is a little more important, but the simple answer is that both numbers matter.
Let's review some of the basic facts about blood pressure.
Normal blood pressure is 120/80 or below. I'm often asked, "What is a normal blood pressure for my age?" The answer is much simpler than most people realize: Less than 120/80. While it's true that blood pressure tends to rise with age, that's no reason to feel complacent: Such a rise will always carry with it an increased risk of heart attack, stroke, kidney failure, and other complications of high blood pressure (hypertension).
Blood pressure normally varies throughout the day, often by 40 points or more. Exercise and stress are especially likely to increase it, while relaxation and sleep will usually lower it. Standing up or talking, for example, can increase blood pressure by 10 or more points. Even simply worrying about blood pressure will increase it. If your blood pressure is only high when you're exercising or when you're at the doctor's office, that's okay. But if it's high even part of the time in routine situations, that is abnormal and deserves treatment.
High blood pressure is anything above 120/80. However, mild elevations beyond those numbers only slightly increase the risk of significant health problems. We generally don't prescribe medication to bring down blood pressure until the systolic reaches 140 or the diastolic reaches 90. The exception is for people with diabetes or impaired kidney function, in whom we use medication for anything above 130/80. That's because people with diabetes and kidney disease are already at higher risk for heart attack and stroke.
Treating high blood pressure takes more than just medication. If your blood pressure is ever above 120/80, you can improve your overall health by lowering it, even if you don't need medication. Losing weight, exercising regularly, and limiting your sodium (salt) and alcohol intakes are proven ways of reducing blood pressure. Such treatments don't cost any money and the only side effect is likely to be improved health!