For some strange reason, people will vigorously deny having high blood pressure. "I'm nervous." "I fought traffic to get here!" "You wouldn't believe the stress I'm under!" or "Wait until I relax a little while and it'll come down." All are common reactions of those advised their pressures are high.

Yet high blood pressure, even by relatively lax definitions, is destined to affect the majority of Americans. Succumb to popular food and exercise patterns, and high blood pressure is as inevitable as death and taxes. Even if you're non-hypertensive at age 55, the Framingham Heart Study predicts a 90% likelihood you'll be hypertensive during your lifetime.

Added to the inevitability of high blood pressure, conventional blood pressure treatment does not fully erase the risk of cardiovascular events from hypertension (according to the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, or JNC-VII 2003). In other words, threats to health from high blood pressure remain uncorrected even when blood pressure is fully controlled by medication (when conventional blood pressure targets are reached).

Like changing the oil in your car, proper management of blood pressure is a necessary prerequisite to obtaining full control over health. You can baby your car, wax it, lube and tune it, but neglect oil changes and you'll never get full life out of your car. In the same way, blood pressure control is a basic and absolute requirement in your effort to maintain optimal health.

Why so much fudging on blood pressure?

One factor is that blood pressure is variable. In the morning, just after arising, maybe your blood pressure is 104/78. Eat breakfast, have coffee, and your blood pressure is 128/74. Sit at your desk at work, have another cup of coffee, answer e-mails, take some phone calls, and you're now at 149/79. Eat lunch, perhaps overeat, sit back down: 140/64. A really annoying comment from a customer, blood pressure now: 164/68. Blow off steam with a friend, walk 200 feet to another part of the building, look at the picture of your family on your desk and remind yourself that there's more to life than work; pressure now 130/70.

Life has many variables. So does blood pressure: Time of day; what you ate for your last meal; hormonal shifts; amount of sodium, calcium, potassium, or magnesium in your diet; your vitamin D status; mood; use of diuretics like caffeine; and so on. It's no wonder blood pressure varies!

Blood pressure fluctuates in people with normal blood pressure. Blood fluctuates in people with high blood pressure, too, but it fluctuates more widely and stays in a higher range more frequently and for longer periods. But a person with normal blood pressure can occasionally have high blood pressure; a person with high blood pressure can occasionally have normal blood pressure. It's all a matter of degree and duration.