It would be great if studies showed that we didnâ€™t have to worry so much about keeping our blood pressure from getting too high.Â But, thatâ€™s not the case.Â In fact, studies have been increasingly showing us that we need to adjust the â€œnormalâ€ range to a bit lower than we had it in the past.Â
For decades, 120/80 was considered a â€œnormalâ€ blood pressure, sending a message that this was an ideal blood pressure. And readings of 135/88 were â€œfine.â€ The reality may be that you would be better off if your blood pressure stays below 120/80 and that 135/88 is actually too high.
The first major warning that the old â€œnormalâ€ is not ideal came when the National Heart, Lung and Blood Institute published its new hypertension guidelines in 2004. The guidelines pointed out that the risk of heart attack and stroke increases when systolic blood pressure (the top number) is greater than 115 mmHg and diastolic blood pressure (the bottom number) is greater than 75 mm Hg. For every 20-mm-Hg increase in systolic pressure or 10-mm-Hg increase in diastolic blood pressure, your risk of dying from cardiovascular diseases doubles. Based on this information, the new guidelines defined a large number of people with readings between 120-139 over 80-89 as â€œprehypertensive,â€ a label that indicates some action is needed, not necessarily drugs, to bring those numbers down.
A lot of physicians thought that the hypertension experts got kind of carried away. However, research is coming along that strongly suggests the â€œaggressiveâ€ guidelines to be correct.
For example, a study published a couple years ago tested two different drugs for hypertension in 1,991 patients with coronary artery disease, all of whom had â€œnormalâ€ blood pressures. The average blood pressure at the beginning of the two-year study was 129/78 mm Hg.
The patients were randomly assigned to get a calcium blocker drug (amlodipine, also known as Norvasc), or an ACE inhibitor (enalapril, also know as Vasotec), or a placebo. Both drugs lowered systolic blood pressures by about 5 mm Hg, and diastolic pressures by about 2.5 mm Hg.
During the two years of follow-up, cardiovascular complications occurred to 23% of the patients who received placebo, compared with just 17%of those who received amlodipine and 20% of those who received enalapril.
Especially interesting were findings on atherosclerosis in the subjectsâ€™ coronary arteries. The atherosclerosis had progressed in the patients who received placebo, but not in those who had received either blood-pressure-lowering drug.
The study still gets a lot of attention because it supports the belief that we are not setting our blood-pressure goals low enough. This more aggressive goal may make sense, but we havenâ€™t come close to getting the people with diagnosed hypertension, that is, people with readings over 140/90, into range. Some estimates say that two-thirds of people currently diagnosed with hypertension do not have good blood-pressure control.
Getting blood pressure to really low levels is not so easy. You can only push blood pressure so low before people get light-headed, and perhaps even pass out. Most people start to get symptoms like these when systolic pressure (the top number) goes below 80 to 90. That said, very few patients with hypertension have blood pressures anywhere near this range.
The main message about blood pressure is that doctors and patients need to work harder to bring it under control. If you are working under the â€œold normalâ€ guidelines, then talk to your doctor about the â€œnew normalâ€ range.Â You might find that you need to be more aggressive about your treatment and make further lifestyle adjustments.Â Weight loss, regular exercise, and a diet rich in fruits and vegetables with less salt help to lower blood pressure and can make blood pressure drugs more effective. There are plenty of things you can do to get your blood pressure in the proper range.Â Talk to your doctor about medication choices. The right drugs are the ones that work for you and that you take every day.
Reducing your blood pressure even a little bit can dramatically improve your health and life expectancy. Harvard Medical Schoolâ€™s report, Hypertension: Controlling the silent killer, lays out a step-by-step lifestyle program you can use to lower your blood pressure. It also covers blood pressure monitoring and medications. With the information available today, there is no need for hypertension to be a killer any longer.