A partial blockage of a coronary artery may not cause noticeable symptoms. But, as the blockage worsens, it can cause symptoms such as chest tightness, difficulty breathing, and dizziness. This is a medical emergency.

A heart blockage can happen when fatty material known as plaque builds up in the arteries leading to your heart. When plaque accumulates in your arteries, it lowers the amount of blood that can flow to your heart. If blood flow to your heart is completely blocked, it can cause a heart attack.

A partial heart blockage may not cause symptoms. But, as the blockage gets more severe, it can cause symptoms like shortness of breath, chest pain or tightness, and dizziness. If you have these symptoms, it’s important that you get immediate medical attention.

Although there are ways to monitor your heart health at home, it’s not safe to self-diagnose a serious condition such as a heart blockage. Any time blood flow is restricted to your heart, it’s a medical emergency.

If your doctor determines that you have plaque buildup inside your arteries, they’ll work with you to create a treatment plan to lower your risk of a heart attack.

A heart blockage can occur when a sticky substance known as plaque accumulates in the arteries that supply blood to your heart. Plaque is made up of fat, cholesterol, cellular waste products, calcium, and a clotting substance known as fibrin.

When plaque builds up in your blood vessels, it can cause a narrowing of your arteries — a condition known as atherosclerosis. This can make it more difficult for blood to flow through the arteries in your body.

About atherosclerosis

Approximately half of Americans between the ages of 45 and 84 have atherosclerosis and are unaware that they have this condition. According to medical experts, atherosclerosis is the leading cause of death in the United States due to the many diseases and complications it can cause.

Complications of atherosclerosis can include:

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The narrowing and hardening of the arteries that supply your heart with blood is known as coronary artery disease. If too much plaque accumulates in these arteries, it can cause a complete blockage and lead to a heart attack.

Additionally, a heart blockage can be caused by a piece of plaque that breaks away from an artery wall. This can lead to a blood clot in a coronary artery, which can also trigger a heart attack. If blood flow isn’t restored as quickly as possible, the heart muscle will begin to die.

Blockages in coronary arteries tend to develop slowly over the course of many years. People who have a partial blockage may not have symptoms. Or they may only notice symptoms when their body needs more oxygen than usual, e.g., during physical activity or when they feel stressed or anxious.

Early symptoms of a partial heart blockage may include:

  • feeling more tired than usual
  • chest discomfort (angina)
  • difficulty breathing, especially when you exert yourself
  • lightheadedness or dizziness

The symptoms of coronary artery disease are often split into grades. These grades describe early to late symptoms, with grade 4 being the most serious.

  • Grade 1: Chest pain that occurs in response to sudden increases in physical activity or emotional distress, not during everyday activities.
  • Grade 2: Chest pain that occurs during activities like fast walking, uphill walking, climbing stairs after meals, or when you’re cold or upset.
  • Grade 3: Chest pain that occurs during low impact activities like light walking.
  • Grade 4: Chest pain that occurs even at rest or when doing minimal activities.

If you have any symptoms of coronary artery disease, be sure to follow up with a medical professional as soon as possible for a proper diagnosis.

When to get immediate medical care

A complete heart blockage can result in a heart attack. Get immediate medical attention if you have symptoms such as:

  • chest pain or chest tightness
  • pain in the upper back, arms, shoulders, neck, or jaw
  • trouble breathing
  • nausea or vomiting
  • sweating
  • extreme fatigue
  • dizziness or lightheadedness
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If you have symptoms that are consistent with a blockage in a coronary artery, your medical team will run a series of tests. These tests may include:

  • an electrocardiogram to check the electrical activity of your heart
  • imaging tests such as an echocardiogram or magnetic resonance angiography to see how blood is flowing to and around your heart
  • cardiac catheterization, which involves having a thin tube (catheter) inserted into an artery and threaded to your heart — this allows your doctor to view areas around your heart where plaque may have built up
  • coronary calcium scan to measure the amount of calcium or calcium calcification in your arteries
  • blood tests to check your cholesterol, triglycerides, lipoproteins, and proteins that signal inflammation
  • a stress test to assess blood flow to your heart or to determine whether there are irregularities in the walls of the heart

Heart blockage treatments

If you have a heart blockage, a doctor will usually recommend a combination of lifestyle changes, medication, or, in some cases, surgery.

Lifestyle changes may include:

Medications may include:

Some types of heart blockages may require surgical procedures, such as angioplasty and stent placement or heart bypass surgery.

If you’ve received a diagnosis of coronary artery disease, your doctor may recommend keeping an eye on your heart health at home.

It’s not possible to self-diagnose a heart blockage or other heart-related issues. But there are ways to monitor your heart health and inform your doctor immediately of any changes.

Monitor your blood pressure

Your healthcare team can help you understand how to measure your blood pressure at home and what type of blood pressure monitor to purchase.

A healthy blood pressure range is generally considered to be less than 120/80 mm Hg. This can vary depending on your age, gender, weight, medications you’re taking, and your overall health.

Monitor your heart rate

Measuring your heart rate can tell you how hard your heart is working. To measure your pulse, place two fingers on your wrist and count how many beats you feel in one minute.

A healthy resting heart rate is usually between 60 and 100 beats per minute.

Take the stair test

One indicator of how well your heart is working is to see how quickly and easily you can walk up a flight of stairs.

According to a 2020 study, being able to climb about four flights of stairs (approximately 60 stairs) in 90 seconds or less may be an indicator of a healthy heart.

A heart blockage is caused by plaque buildup in the arteries that supply your heart with blood. A partial or minor heart blockage may not cause any symptoms. But a complete blockage can cause serious complications, such as a heart attack.

If you have symptoms of a heart blockage, it’s important to get immediate medical attention. These symptoms can include chest pain, shortness of breath, difficulty breathing, and dizziness.

You can monitor your heart health at home by taking regular blood pressure readings, measuring your heart rate, and taking the stair test. If you notice any changes, be sure to let your doctor know right away.