Whether your blood pressure teeters on the high side or skitters along the low end, it’s important to know your numbers. We asked doctors to explain what those readings mean, how hypertension and hypotension can affect your body, and steps you can take to keep your blood pressure in check to protect your health.
[the basics of hypertension]
To paraphrase Mark Twain, a high blood pressure diagnosis is becoming as common as an opinion—almost everybody has one. High blood pressure, also called hypertension, can lead to heart disease or failure, stroke, kidney failure, and other problems. Protect your health by better understanding this common problem.
the new normal
If you’ve been diagnosed with hypertension, you’re not alone. Nearly one in three adults has high blood pressure, and about two-thirds are 65 or older, says Dr. Marie Philipneri, a nephrologist and co-director of the SLUCare Hypertension Clinic. “The prevalence of high blood pressure has increased over the past two decades,” she says. In 2001, 26.5 percent of adults in Missouri had high blood pressure; today, it’s more than 35 percent. African-Americans in the state have about a 5 percent higher prevalence of hypertension than Caucasians.
“Hypertension is the most common reason for someone to come into the clinic for medication,” says Dr. Anne Jacob, a family medicine physician with SSM Health Medical Group at SSM St. Mary’s Health Center.
measure up
For the uninitiated, ‘blood pressure’ means the force of the blood that pushes against your arterial walls when your heart beats. If the pressure goes up and stays high, it can cause damage. To determine your risk, your doctor will frequently measure your pressure. The reading includes two numbers—the larger (systolic) is the pressure at the peak of a heartbeat and the smaller (diastolic) is the base pressure between heartbeats.
The U.S. Centers for Disease Control defines normal blood pressure as 120/80 or lower, and a person is considered pre-hypertensive above that level. Hypertension begins at 140/90. A person’s blood pressure can vary at different times, but if the numbers stay high most of the time, you’re likely at risk for health problems.
the why
Most cases of high blood pressure arise on their own. “The vast majority of patients with high blood pressure, more than 90 percent, have essential hypertension without any identifiable cause,” Philipneri says. Genetics account for about 30 percent of high blood pressure cases, Jacob says. “If one or both of your parents has high blood pressure, your chances are twice as likely to have it, too. These are factors you cannot change beyond a point.”
A small number of patients have hypertension caused by another disease. “Anywhere from 5 to 10 percent of patients have secondary hypertension, meaning a potentially treatable cause could be identified,” Philipneri says. These disease causes include diabetes, kidney disease, thyroid or adrenal gland problems, sleep apnea, obesity and coarctation of the aorta, a rare narrowing the of the heart’s main artery.
Many prescription medications, such as birth control pills, pain relievers, hormone replacements and decongestants, can boost blood pressure, Jacob says. “Excessive alcohol use and illicit drugs can be causes, and vitamin D deficiency has been identified as a possible cause recently.”
Personality type also can be a source of high blood pressure, she says. “If you have a hostile, Type-A personality or depression, that can be a cause of high blood pressure,” Jacob adds. Tobacco smoking, a high-salt diet, low potassium intake, and a number of over-the-counter and herbal remedies also may contribute.
Continuing increases in blood pressure can be expected as we age and our blood vessels get stiffer, Jacob says. The years also may bring atherosclerosis, a disease caused by plaque accumulating inside the arteries. The plaque consists of cholesterol, fat and calcium that can harden and narrow the arteries. “As the blood vessels become stiffer, the blood pressure goes up,” she says.
[taking control]
With such a significant portion of the population struggling with high blood pressure, something must be done. There are options for getting hypertension under control, including lifestyle modifications and medications.
mitigate your risk
“Blood pressure is a marker of your overall health. It has to remain at a certain level,” says Dr. Jennifer Chung, who practices internal and geriatric medicine at Mercy Internal Medicine Clinic on Old Tesson Road. “If it is above that level, it can damage many organs in your body and predispose you to heart attacks, strokes, kidney disease and many other problems.”
For most people, the body keeps blood pressure relatively well controlled, says Dr. Michael Klein, a cardiologist at Missouri Baptist Medical Center. For the one-third of Americans who have hypertension, however, it may require additional work to get the numbers in check. “The important thing to remember is that in almost all cases blood pressure can be brought under control,” Klein says.
tipping the scales?
High blood pressure often arises from our genetic blueprint, so healthy habits alone generally won’t resolve it. “Some people can’t expect to completely cure their blood pressure just by weight loss or dietary changes because something else keeps it elevated,” Chung says.
If your health and personal habits are contributors, however, cleaning them up can make quite a difference. “High blood pressure is common in people who are overweight or obese and people who enjoy a lot of salt in their diet,” Chung says. “Too much salt can cause the body to retain fluids, which causes higher blood pressure.” Patients can sometimes see positive results by changing their diets, losing weight and exercising.
medications
While lifestyle alterations can help lower blood pressure in many less-advanced cases, Klein points out that more advanced cases require a variety of medications. Some basic medications work by controlling the heart rate, Chung explains. “Others work directly on the blood vessels and help them relax. Some cause you to urinate some of the salt and fluids in the body,” she says.
Of course, Chung reminds, “every medication has side effects, and every person is unique in his/her genetic makeup. A lot of people can take these medications without side effects, but it is difficult to tell who is going to react.” Your doctor will monitor your reaction to medications to determine what will work best for you. “Some people have high blood pressure when they are younger, then it begins to drop as they get older,” she says. “ But many people need to stay on this medication for life.”
[the other extreme: hypotension]
You might think low blood pressure would be a great problem to have. But it can cause dizziness and fainting, and even be life-threatening in severe cases. Although there’s no specific number at which hypotension is diagnosed, it’s important to get treatment if symptoms appear.
how low is too low?
Is it better to have hypotension? “A lot of people believe low blood pressure should be a good thing, but when we have low blood pressure, we can have problems getting enough blood to the brain and vital organs,” says Dr. Victoria Spencer, a family physician at St. Anthony’s Medical Center.
Blood pressure is very individualized, so hypotension is not diagnosed by a specific number. While some doctors consider any top number under 100 as low blood pressure, most define it as something that causes symptoms, says Dr. Joseph Craft, a cardiologist at The Heart Health Center in Creve Coeur. “Decreased blood flow to the head might make someone feel light-headed or pass out,” he says. “Prolonged low blood pressure causing decreased blood flow to the kidneys may impair kidney function, so the kidneys may not filter the blood well.”
Ideally, Spencer says, “we want people to have normal blood pressure so the heart is supplying all of their organs with the oxygen and nutrients that are needed.”
the causes
There are many things that can lower your blood pressure, Craft explains. “Dehydration can cause the pressure to be low,” he says. “Some medicines are too much for some people; the doses can be too high relative to the patient’s needs. Heart attacks and severe infections are other causes.”
When young people encounter hypotension, the cause almost always is dehydration, Spencer says. She adds that congestive heart failure, critical illnesses and certain combinations of medications also can lower blood pressure. The latter include prescriptions given for depression and diuretics prescribed to reduce swelling.
Older patients are more vulnerable to aorthostatic hypotension, a phenomenon where blood pressure drops with sudden changes in body position, Craft says. “When some people stand, their blood pressure drops, and they can feel woozy, light-headed or nauseous, or even fall.” Compression stockings and adjusting eating habits can be helpful in reducing the problem, Spencer says.
Rare diagnoses of low blood pressure may be linked to low salt consumption, she adds. “I have had a couple of patients who had hypotension and low sodium levels. They heard salt was bad so they cut it out of their diets completely.”
take note
There probably is little reason to be concerned if the only indication of low blood pressure is the reading on the gauge. “That usually doesn’t warrant monitoring, if you feel well,” Craft says. “If you want to be reevaluated, rely on your relationship with your doctor. It is good to be thoughtful, but if your systolic top number is between 100 and 135 it is not something you need to be very vigilant about.”
If there are symptoms, however, “Don’t brush it off,” Spencer says. “It is not fun to feel dizzy every day. If you are feeling some dizziness or are feeling faint, talk to your doctor about it. The treatment can be just small behavioral changes.”