Living with uncontrolled hypertension (high blood pressure) damages your blood vessels over time and causes your heart to work harder. It can also lead to plaque build up in your arteries (called atherosclerosis) and puts you at high risk for a heart attack or stroke.

The key to protecting your heart health begins with understanding high blood pressure and its impact. Here’s what you need to know about uncontrolled hypertension, including how it affects your heart and when to get medical attention for a hypertensive emergency.

What Is Uncontrolled Hypertension?

When blood pushes too forcefully against your arteries’ walls, your blood pressure is high and the condition is called hypertension. And when it’s uncontrolled, it can lead to a number of health issues like heart attack, stroke, and cognitive decline. But what do doctors mean when they say you have uncontrolled hypertension?

Someone may have uncontrolled hypertension because they don’t know they have it, so they aren’t taking the medications needed to keep their readings within the normal range of 120/80 millimeters of mercury (mm Hg). One study found that nearly 60 percent of adults over the age of 18 with hypertension didn’t know they had the condition.

In other cases, people are aware of their condition, but the medications they’re taking aren’t keeping their blood pressure under control.

When the latter happens, healthcare providers label this condition resistant hypertension. Typically, you have resistant hypertension when all of the following are true:

• You’re taking three different blood pressure medications and your blood pressure is still too high.
• Part of your treatment plan includes taking a diuretic (a medication that helps remove excess fluids and salt).
• Your blood pressure is consistently higher than 130/80 mm Hg (or the goal established by your healthcare provider).
• You have to take four or more medications to control your hypertension.

About 20 percent of people with high blood pressure have resistant hypertension.

How Does Persistent High Blood Pressure Affect Your Heart?

When your arteries are healthy, the interior is smooth, which allows your blood to move easily throughout your body, carrying essential nutrients and oxygen to your most important internal organs. Healthy vessels are also flexible yet sturdy, keeping your blood flowing normally and your body functioning as it should.

Hypertension damages the walls of your blood vessels. It starts by narrowing your arteries and allowing fats from food to collect in the damaged vessels. Over time, this causes your arteries to become less elastic and ultimately impacts blood flow.

High blood pressure can even predispose your arteries to developing aneurysms (or bulges in the artery walls). These aneurysms, which are most common in your aorta (your largest artery), can burst open and cause internal bleeding.

Uncontrolled high blood pressure can lead to irregular heartbeats or arrhythmias as well as an enlarged heart. This extra work can also cause your heart to thicken and get bigger, especially in the left ventricle. When this happens, it puts you at a higher risk for heart attack and heart failure.

What Are the Consequences of Uncontrolled Hypertension?

Uncontrolled hypertension can lead to a number of health issues, including heart attack, stroke, heart failure, chronic kidney disease, atherosclerosis, and more.

Here’s a closer look at how high blood pressure leads to heart complications:

• Heart attack — Hypertension is a risk factor for blockages in your arteries and prevents blood flow to your heart muscle. When this happens, it can cause a heart attack.
• Heart failure — When you have high blood pressure, your heart muscle has to work harder, which can cause your heart to get bigger and thicker. This makes it more difficult to pump blood to the rest of your body, which can lead to heart failure in severe cases.
• Atherosclerosis — Hypertension makes your arteries more susceptible to damage and allows plaque to build up, making arteries narrow and stiff. This makes it harder for blood to flow properly.
• Coronary artery disease — When atherosclerosis occurs in arteries that supply the heart, the condition is known as coronary artery disease (CAD). Blood has more trouble flowing through narrow blood vessels.
• Stroke — Hypertension can affect the blood vessels responsible for supplying blood and oxygen to your brain. This damage can then lead to blockages or even cause blood vessels to burst.
• Arrhythmia — Having uncontrolled hypertension for a long time is a risk factor for certain patterns of irregular heart rhythm, known as arrhythmias.

Uncontrolled hypertension can cause other health complications beyond your heart. Possible complications include:

• Kidney disease — When your arteries are damaged by hypertension, it can make it harder for your kidneys to filter blood correctly. This can lead to kidney disease and even kidney failure.
• Vision changes or loss — The blood vessels in your eyes can be impacted by high blood pressure. The changes in blood flow can strain and damage your eyes or even cause blindness.
• Sexual dysfunction — Damage to blood vessels can lead to lower sex drive and erectile dysfunction (not being able to have an erection).

Why You Should Treat Hypertension

Hypertension is a preventable and treatable risk factor for heart disease and stroke. Yet nearly 93 million people in the U.S. haven’t controlled their blood pressure.

The Centers for Disease Control and Prevention (CDC) estimates that better blood pressure control could potentially prevent over 115,000 cardiovascular deaths, more than 91,000 heart attacks, and 139,000 strokes in adults with uncontrolled hypertension.

It starts with getting regular physicals from a healthcare provider, making appropriate lifestyle changes, and staying in close touch with your doctor to monitor how your blood pressure treatment plan is working.

When To Get Emergency Help for High Blood Pressure

Most of the time, hypertension doesn’t come with any symptoms. But if it reaches dangerously high levels, it can cause a hypertensive emergency, especially if you experience blood pressure that is 180/120 mm Hg alongside the following symptoms:

• Chest pain
• Difficulty breathing or shortness of breath
• Noticeable back pain
• Numbness or weakness
• Difficulty seeing or a change in vision
• Challenges speaking
• Memory loss or trouble concentrating
• Severe headache

If your blood pressure is high and you’re having symptoms, this is a medical emergency, and you need medical attention right away. Call 911 or get to an emergency room.

If you have extremely high blood pressure but no symptoms, it’s likely you have severe hypertension. Make an appointment with your healthcare provider as soon as possible to discuss ways to manage your high blood pressure.

Join the Conversation

On MyHeartDiseaseTeam, people share their experiences with heart disease, get advice, and find support from others who understand.

If you have uncontrolled high blood pressure, what have you done to try to lower your blood pressure readings? Let others know in the comments below.