By Roberta H. Anding, MS, Baylor College of Medicine and Texas Children’s Hospital
Edited by Kate Findley and proofread by Angela Shoemaker, Wondrium Daily
Hypertension or high blood pressure is one of the most pervasive chronic disorders facing Americans. Professor Anding explains its consequences and why you should regularly monitor your blood pressure.
Prevalence of Hypertension
According to the National Center for Health Statistics (NCHS) and the National Heart, Lung, and Blood Institute (NHLBI), the prevalence of hypertension in the United States varies by ethnic group. No matter your ethnicity, though, monitoring your health for signs of high blood pressure is essential.
In the United States, one out of three people is diagnosed with high blood pressure. Over one billion people worldwide every year are diagnosed.
What are the consequences? Uncorrected high blood pressure can lead to congestive heart failure, heart attack, stroke, and arterial aneurysm—where the walls of the blood vessel become dilated.
What Is High Blood Pressure?
High blood pressure is the leading cause of chronic kidney or renal failure in the United States, leading to dialysis. Even a moderately elevated blood pressure can lead to a shorter life expectancy.
Not everybody has signs and symptoms of high blood pressure, requiring careful monitoring of your health. What constitutes high blood pressure?
Blood pressure is the force of the blood pumping against the arterial walls. Sometimes this is defined as cardiac output—how hard the heart is pumping—or peripheral resistance—the kind of resistance the blood meets as it flows through the blood vessels.
Monitoring Blood Pressure
For adults, normal blood pressure is considered 120 over 80 millimeters of mercury. Even slight elevations above this number can cause health problems.
That systolic number is the top number. Previously, it was thought that this was not a very important number. We don’t really know the magnitude or the effect of high systolic pressure, but that’s the force of the blood when the heart beats.
Most recently, multiple studies suggest that decreasing that systolic blood pressure by 12 to 13 millimeters of mercury over a four-year period of time can reduce the incidence of stroke by 37%. The take-home message is that top number matters for your health.
Diastolic pressure is the bottom number. It represents the force in between heart beats and is a more important risk factor for those under the age of 50. According to the American Heart Association, the pattern and significance of high blood pressure changes depending on your age. Thus, under the age of 50, you should focus on the diastolic number.
Over the age of 50, it’s the systolic number that you should focus on. Both of these numbers play a role in your overall health. The systolic number often represents the stiffness of those blood vessels. As we age, we end up with plaque in our arteries, which stiffens the blood vessels slightly.
What to Look For
Even if you have normal blood pressure at age 55 or older, Professor Anding encourages you to continue monitoring it because, in general, people still have a 90% lifetime risk of high blood pressure. The emphasis on monitoring blood pressure is found in the Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure.
The committee suggests that for every 20 millimeter mercury rise in systolic pressure and 10 millimeter mercury rise in diastolic pressure, you double the risk of heart disease. That’s why this monitoring makes a difference.
There also is an early warning sign that your body may give you—like a light on the car dashboard indicating you should pay attention. Pre-hypertension is defined as a blood pressure from 121 over 81 millimeters of mercury to 139 over 89 millimeters of mercury.
It indicates whether you are at risk of developing hypertension. As the science emerges, this category may become more relevant over time. Tomorrow’s article will delve into risk factors for high blood pressure.
Professor Roberta H. Anding is a registered dietitian and Director of Sports Nutrition and a clinical dietitian at Baylor College of Medicine and Texas Children’s Hospital. She also teaches and lectures in the Baylor College of Medicine’s Department of Pediatrics, Section of Adolescent Medicine and Sports Medicine, and in the Department of Kinesiology at Rice University.
