Can High Blood Pressure Cause a Heart Attack? Here’s What You Need To Know

If you’ve been diagnosed with high blood pressure (hypertension), you may be wondering: Can high blood pressure cause a heart attack?

The short answer is yes — high blood pressure (BP) can cause heart attacks, both directly and indirectly. Cardiologist Luke Laffin, MD, explains how.

How high blood pressure can raise heart attack risk

Chronic high blood pressure raises your risk of heart attack by:

• Damaging your arteries: In the same way that a high-pressure hose can damage your skin, high blood pressure can harm the inner lining of your arteries. These damaged areas are prime spots for fat and cholesterol to form plaques.
• Promoting plaque buildup: “High blood pressure increases your risk of atherosclerosis, which is when plaque accumulates in the arteries of your heart, narrowing them and restricting blood flow,” Dr. Laffin explains. This increases the risk of a blockage, the most common cause of heart attacks.
• Causing blood clots: Plaque ruptures trigger your body’s clotting mechanism. If the resulting blood clot is large enough to cause a blockage, it can trigger a heart attack.
• Straining your heart: Some heart attacks happen because high blood pressure forces your heart to work too hard for too long, thickening or weakening the muscle. That strain can happen quickly (in a hypertensive crisis, for example), or it can happen over time, as it does with heart failure. “If your heart can’t pump blood efficiently enough to meet your body’s — including your heart’s — demand for oxygen and nutrients, it can cause a heart attack,” Dr. Laffin further explains.

Does blood pressure change during a heart attack?

While high blood pressure raises your risk of a heart attack, that doesn’t mean your blood pressure has to be high while you’re having one. It can be high, low, in a healthy range or even bounce between all three.

“There isn’t one specific way that blood pressure behaves during a heart attack,” Dr. Laffin clarifies. “In fact, a heart attack itself doesn’t necessarily change your blood pressure at all. Your blood pressure can change throughout the course of a heart attack, but it can also stay the same.”

What happens to your blood pressure during a heart attack depends on:

• What’s causing the heart attack: If your heart attack is the result of a hypertensive crisis (a sudden, sharp increase in your blood pressure), it’s likely to look different from a heart attack caused by plaque rupture in the coronary arteries.
• The kind of heart attack you’re having: A silent heart attack may not cause a noticeable change in your blood pressure, for example.
• You: Your age, health history, medications, stress levels and more can affect your blood pressure, even in the middle of a heart attack.

Why it’s important to manage high blood pressure

In the long term, unmanaged high blood pressure significantly raises your risk of heart attacks and other conditions, like:

• Stroke
• Heart failure
• Kidney disease
• Dementia

“Nobody wants any of those things, so it’s crucial that we get your blood pressure into a healthy range,” Dr. Laffin says.

Of course, that can be tough to do. Genetics, chronic health conditions, access to healthcare and a host of other factors can be a barrier to better BP. In fact, a recent study found that 71% of U.S. adults with high blood pressure who were on medication still weren’t in a healthy range.

The good news? Research shows that even a modest drop in blood pressure can reduce your risk of heart disease. So, start with small, achievable goals. In time, that 10-minute walk after dinner or salt-free snack break can add up to big progress.

When to get help

It can be hard to know when high blood pressure is an emergency because the numbers on your blood pressure monitor don’t tell the whole story.

“There’s no specific threshold,” Dr. Laffin says. “You could have a blood pressure of 190/110 and not necessarily need to rush to the emergency department. New symptoms are the thing to look out for.”

Call 911 or local emergency services if your blood pressure is high and you:

• Are short of breath
• Feel pain or pressure in your chest
• Have a severe headache
• Notice changes to your vision
• Are dizzy, confused or unusually anxious
• Fainted or had a seizure
• Feel numb or weak
• Vomited (or feel like you’re going to)

What if your blood pressure is unusually high, but you don’t have any other symptoms? Dr. Laffin advises calling your primary care provider or cardiologist. They can help you decide next steps.