High Blood Pressure: Symptoms, Treatments, and Causes

High blood pressure rarely causes any symptoms, which is why knowing your numbers and taking steps to make sure they are where they need to be is your best defense against heart attack and stroke.

If you've been told that you have high blood pressure, you're not alone. Far from it, actually.

Almost 1 in 4 Canadian adults are affected by high blood pressure (or hypertension), and almost half of them don't have it well controlled.

With high blood pressure, the force of blood flowing through your blood vessels is consistently too high. When it goes undiagnosed and/or untreated, high blood pressure can dramatically increase your risk for heart attack, stroke, kidney disease, and vision problems by damaging blood vessels.

Early diagnosis and treatment is vital

The force of high blood pressure damages the lining of the arteries, which allows "bad" low-density lipoprotein (LDL) cholesterol plaques to set up camp, potentially blocking blood flow and causing a heart attack or stroke. The more plaque and damage, the narrower the insides of the arteries.

You can't feel high blood pressure—so the only way to know you have it is to get tested. This information will give you a running start against the consequences of uncontrolled high blood pressure.

"We need to be hyper-vigilant about high blood pressure because it's a silent killer," says Mike Farbaniec, a cardiologist at Penn State Health Milton S. Hershey Medical Center in Hershey, Pennsylvania. "Make sure you see your doctor when you are in your 30s to 50s. If you hit prevention hard then, you are less likely to be sick in your 60s and 70s."

(Related: Can Anxiety Cause High Blood Pressure?)

High blood pressure risks

Advancing age and a family history of heart disease increase your chances of developing high blood pressure. Other risks include eating an unhealthy diet that contains lots of salt, not exercising regularly, smoking, and drinking too much alcohol.

Obesity and diabetes also raise your risk of developing high blood pressure.

How high is too high?

Systolic blood pressure is the upper number in a blood pressure measurement. It indicates how much pressure your blood is exerting against your artery walls when your heart beats. Diastolic pressure, the lower number, shows how much pressure your blood is exerting against your artery walls when your heart is resting between beats.

A blood pressure reading of less than 120/80 mm Hg is considered normal. High blood pressure is defined as 130/80 mm Hg or higher. But if your blood pressure is somewhere in between, it's considered "elevated." There are dangers of even slightly high blood pressure.

Your doctor should check your blood pressure during your well visits. But these numbers aren't always telltale as some people develop what's known as white coat hypertension, or higher-than-normal blood pressure at the doctor's office because of stress and anxiety.

This is why most physicians will recommend home blood pressure monitoring if you have been diagnosed with hypertension or have risk factors for it, says Farbaniec. "I ask patients to find a cuff and we compare [the measurements taken at home] with ours in office," he says. "If they match, that's great."

Measuring blood pressure at home is empowering, he adds. "When you are in charge of your own screening, you want to do better. It's highly motivating."

Keep track of your readings via an app or with a pen and paper. And discuss them with your doctor at your follow-up visits.

(Related: Can Stress Cause High Blood Pressure? What Heart Doctors Need You to Know)

You have high blood pressure. Now what?

If you have high blood pressure, lifestyle changes are in order, says Luke Laffin, cardiologist at the Cleveland Clinic. This starts with eating a heart-healthy diet that is low in salt, engaging in regular physical activity, and losing weight if necessary.

Diet

Many heart doctors recommend the Dietary Approaches to Stop Hypertension (DASH) eating plan, which is designed to lower blood pressure. In addition to limiting sodium, it also calls for cutting back on red meat and added sugar.

Activity

Exercise is also important. Aim for at least 150 minutes per week of moderate-intensity physical activity. All exercise is good, of course, but moderate aerobic activity—like brisk walking, jogging, or using an elliptical trainer—is best for lowering blood pressure, says Laffin.

Weight

"Losing weight is one of the best things you can do for high blood pressure, and the more weight you lose, the greater the decrease in systolic and diastolic blood pressure," says Farbaniec.

Other lifestyle changes

"Smoking is the biggest risk for high blood pressure, stroke, and heart attack," he adds. If you smoke, quit.

As for alcohol, moderation is key, says Farbaniec. This means no more than two drinks a day for men and no more than one a day for women.

Anxiety and stress can also increase blood pressure. Taking steps to change how you cope with stress will benefit your blood pressure, Farbaniec says. When you're stressed out, you're less likely to do the things you need to do to stay healthy, such as eat right and exercise, and more likely to overdo it with alcohol, he says.

"Take 10 minutes of quiet time each day and pay attention to your breath or meditate," he suggests. "This can dramatically decrease blood pressure over time." There are apps available that can help you learn stress-reduction techniques such as mindfulness or meditation.

(Related: 3 Stretches That Are Good For Your Heart)

High blood pressure medication

Don't beat yourself up if lifestyle changes alone don't get your blood pressure down to where it should be, Laffin says.

"Lifestyle changes only go so far, especially if your blood pressure is extremely high," he says. "After a one- to three-month trial of lifestyle modifications, your doctor may consider adding medication, especially if you have other risk factors for heart disease or a family history of heart disease."

There are many types of medication that can be used alone or in combination to treat high blood pressure. Each has risks and benefits that must be discussed with your doctor based on your health status. In general, side effects of blood pressure medicines may include cough, diarrhea or constipation, dizziness, fatigue, and/or headache.

Common blood pressure-lowering medications include:

Diuretics. Commonly known as "water pills," diuretics get rid of excess salt and water in your body to reduce blood pressure.
Beta-blockers. This class of drugs decreases your heart's rate, workload, and output of blood, which in turn lowers blood pressure.
ACE inhibitors. Angiotensin-converting enzyme (ACE) inhibitors help the body produce less angiotensin, a chemical that causes arteries to become narrow. That helps your blood vessels relax and open up, which, in turn, lowers blood pressure.
Angiotensin II receptor blockers. These medications block the effects of angiotensin, which causes the arteries to become narrow.
Renin inhibitors. These drugs block the enzyme renin from triggering a process that helps regulate blood pressure. As a result, blood vessels relax and widen, making it easier for blood to flow through the vessels, which lowers blood pressure.
Calcium channel blockers. These drugs relax and open up narrowed blood vessels, reduce heart rate, and lower blood pressure.
Alpha blockers. These drugs work by relaxing the muscle tone of the walls of your arteries so that they are more open.
Alpha-2 receptor agonists. These drugs reduce blood pressure by decreasing the activity of the sympathetic nervous system, which releases adrenaline and cortisol, stress hormones that increase heart rate and blood pressure.
Central agonists. These blood-pressure-lowering medications help decrease the blood vessels' ability to contract and tighten.
Peripheral adrenergic inhibitors. These drugs lower blood pressure by blocking chemicals in the brain that instruct blood vessels to constrict. These are mainly used when other blood pressure-lowering drugs don't work.
Vasodilators. These drugs cause the muscle in the walls of the blood vessels to relax so blood flow is smoother.

(Related: 6 Things You Probably Don't Know About Heart Health)

High blood pressure symptoms

While high blood pressure usually does not cause symptoms, some people may experience headaches, nose bleeds, and anxiety when their numbers are high, Laffin says. "We have to really tease out if it's a symptom causing blood pressure elevation or blood pressure elevation causing symptoms," he says.

For example, "a headache can raise your blood pressure because your body responds to pain by elevating blood pressure," he says. High blood pressure can also cause a headache.

Some symptoms such as chest pain, back pain, or vision changes, when they occur with a blood pressure of 180/120 mm Hg or higher, may point to a hypertensive emergency. These are signs of end-organ damage and you should call 911 or get to the emergency room immediately, the American Heart Association warns.

A high blood pressure crisis may cause other symptoms too, including:

Severe headache
Shortness of breath
Nosebleeds
Anxiety

The last word

High blood pressure increases risk of heart attack, stroke, kidney, and vision problems if it is left untreated. Knowledge is power when it comes to high blood pressure. Knowing your numbers and taking the necessary steps to get them where they need to be is the best way to protect your health.

Next: 23 Foods That Help Lower High Blood Pressure