Under pressure: How blood pressure affects heart disease risk
June 6, 2016
One question I hear from patients regularly is, “Dr. Hill, why does it matter so much that I get my high blood pressure under control?”
High blood pressure, also known as hypertension, is an extremely common condition and a major risk factor for heart disease. Nearly one in three Texas adults has high blood pressure — were diagnosed in 2010. And the scary thing is many don’t have the condition under control.
Uncontrolled hypertension can lead to heart attack and stroke. That’s why it’s important for you to understand what high blood pressure is, who’s at risk, and how to keep your blood pressure in a range that’s healthy for you.
What is blood pressure?
Blood pressure is the force against the walls of your arteries as your heart pumps blood throughout your body. We use the defined by the American Heart Association to guide us when diagnosing and treating hypertension.
When your doctor measures your blood pressure, you’re given two numbers – your systolic pressure and your diastolic pressure:
- Your systolic pressure (the top number) is the pressure in your arteries as your heart beats. “Normal” systolic pressure is less than 120 millimeters of mercury (mm Hg).
- Your diastolic pressure (the bottom number) is the pressure in your arteries in between heartbeats. “Normal” diastolic pressure is less than 80 mm Hg.
For the average person who is not at high risk for hypertension, we aim for a total blood pressure of 120/80 or lower. If your blood pressure is higher than 120/80, you could be at risk for heart disease.
Who’s at risk for high blood pressure?
As we age, our risk for high blood pressure increases. More than 76 percent of men age 75 and older have it, and nearly 80 percent of women have high blood pressure by the time they reach age 75. It has been said that hypertension is a “disease” that everyone will get if they live long enough!
In addition to age, factors that can increase your risk for hypertension include:
- Being African-American
- Being obese
- Drinking too much alcohol
- Eating an unhealthy diet (too much salt, not enough potassium)
- Getting too little exercise
- Having a family history of high blood pressure
- Having diabetes
- Using tobacco
High blood pressure: The “silent killer”
Some people believe they can feel when their blood pressure is high. Unfortunately, that’s not true.
Many people who have high blood pressure have no idea they have it because it has no signs or symptoms. That’s why we call high blood pressure the “silent killer.”
You may not be able to feel your high blood pressure, but it’s definitely damaging your body. The American Heart Association warns of many possible consequences of high blood pressure, such as:
- Angina (chest pain)
- Damage to the heart and coronary arteries
- Peripheral artery disease (a narrowing of the arteries to the head, stomach, arms, and legs)
Your brain on high blood pressure
Your brain is not equipped to handle high blood pressure, so your body tries to protect the brain by shielding it. Your blood vessels will constrict, or narrow, to prevent the brain from the increased pressure the rest of your body is dealing with. This a dangerous situation for the brain on a long-term basis.
That’s one of the challenges we face in treating high blood pressure: the body’s attempt to adapt. The body tries to adjust as your blood pressure increases over time, but it’s only somewhat effective at doing so.
High blood pressure constantly damages your arteries, which aren’t designed to withstand pressure above the 120/80 range for long periods of time. Under higher pressure, they’re continually forced to try to heal from the damage. This constant damage/healing cycle can promote atherosclerosis, a buildup of substances in your arteries that can reduce or block blood flow and lead to stroke or heart attack.
Change your life – change your high blood pressure
You will have to work together with your doctor to treat your high blood pressure. It’s a team effort, and you’re the most important member of the team. And here’s the good news: It’s rare that we can’t help a patient control his or her blood pressure.
You’ll likely need to make some lifestyle changes to help lower your blood pressure, and we often start with healthier diet choices. A good choice is the DASH (Dietary Approaches to Stop Hypertension) diet, which is promoted by the National Heart, Lung, and Blood Institute to reduce the risk for high blood pressure. Your doctor or a dietitian can help you create a dietary plan that’s best for you.
If you’re overweight or obese, another big step you can take to reduce your risk is to lose weight. Losing just 10 pounds could reduce your blood pressure. Regular exercise can help you lose weight, improve your blood pressure, and promote overall heart health.
Medication for high blood pressure
Lifestyle changes often aren’t enough on their own. Your doctor may prescribe one or more medications to lower your blood pressure. I often have patients who ask me, “Why can’t I just take one pill for my high blood pressure?” Some people safely can, but many can’t.
Here’s the rule of thumb about blood pressure medication:
- About half of all patients with high blood pressure will need two medications to control it
- About one-third will need three medications
- About one-fourth will need four medications
Think of your arteries as plumbing pipes and the medications as tools to support those pipes. If your body has narrowed your arteries to protect you from high blood pressure, it’s like water is flowing inside pipes that are too small. You could reduce the pressure by making the pipe bigger — which we do, by using drugs called vasodilators. Vasodilators widen your blood vessels, allowing more blood to pump through them.
But often, the kidneys get used to the higher blood pressure and they save up fluid until there is enough to “fill the pipe” again — raising the blood pressure back to the high level. If that’s the case, we’ll use a different medication to attack high blood pressure from that angle.
Unfortunately, we can’t safely drop your high blood pressure down to a normal level immediately. As mentioned, your body tries to shield your brain from high blood pressure. If you’ve had hypertension for a long time, the body works in overdrive so the brain feels only the effects of a normal blood pressure. If we immediately lower your blood pressure from 200 to 120, for example, the brain will still be shielded and will feel only the effects of a systolic pressure of about 60. That’s too low, and it can cause many different problems, such as a stroke.
Instead, we lower our patients’ high blood pressure gradually over a matter of weeks. That gives the body more time to adjust as we step down to a safer level. For my older patients, that’s a particular concern because they’re at increased risk for falling. If we lower a patient’s blood pressure too quickly, less blood gets to the brain when he or she gets up out of bed and dizziness can occur.
Better blood pressure for life
Working toward a healthier blood pressure changes the way you live your life. When I prescribe medication for high blood pressure, I tell my patients they’ll likely take it every day for the rest of their lives. They’re often surprised when I say this, but it’s true.
I’ve had patients tell me, “I used to have high blood pressure, but I took this medicine for a while, and it went away, so I stopped taking it.” Or some patients tell me, “I need to take my blood pressure medicine only when I’m feeling bad.”
High blood pressure medication isn’t like the antibiotics you take for a couple of weeks to get over an infection. There’s no “magic pill” or quick fix for hypertension. If you stop taking your blood pressure medicine, the control you have over your high blood pressure will go away.
You didn’t get high blood pressure overnight. You won’t be able to lower it overnight, either. But if you work with your doctor to create a treatment plan, you can successfully lower your blood pressure — and your risk for heart disease.
If you have a family history of heart disease or are concerned about your heart health, request an appointment with a doctor and ask to have your blood pressure checked.