What Is Coronary Artery Disease (CAD)?

Medically Reviewed by Brunilda Nazario, MD on October 19, 2021

clogged artery illustrationCoronary artery disease is also called CAD, coronary heart disease, or atherosclerotic heart disease. It’s a serious condition that happens when plaque builds up in your coronary arteries, which bring oxygen-rich blood to your heart.

Your arteries are smooth and elastic. But when plaque builds up on their inner walls, it can make them stiff and narrow. This slows blood flow to your heart muscle, so it doesn’t get the oxygen it needs.

The plaque could also break off, leading to a heart attack, stroke, or sudden cardiac death. CAD affects millions of Americans.

What Are the Symptoms of Coronary Artery Disease

The most common symptom is angina, or chest pain.

People describe angina as:

  • Aching

  • Burning

  • Fullness

  • Heaviness

  • Numbness

  • Pressure

  • Squeezing

You might mistake it for indigestion or heartburn.

You usually feel angina in your chest, but you might feel it in your:

  • Arms

  • Back

  • Jaw

  • Neck

  • Shoulder

Symptoms are often subtler in women. Nausea, sweating, fatigue, or shortness of breath can join the typical pressure-like chest pain.

Other symptoms of coronary artery disease include:

What Causes Coronary Artery Disease?

Experts think CAD starts with damage or injury to the inner layer of a coronary artery. This damage can even happen when you’re a child. Plaque can start to collect along your blood vessel walls when you’re young and build up as you get older. That buildup inflames those walls and raises your risk of blood clots and heart attacks.

The plaque makes the inner walls of your blood vessels sticky. Things like inflammatory cells, lipoproteins, and calcium attach to the plaque as they travel through your bloodstream.

More of these materials build up, along with cholesterol. That pushes your artery walls out while making them narrower.

Over time, a narrowed coronary artery may develop new blood vessels that go around the blockage to get blood to your heart muscle. But if you’re pushing yourself or stressed out, the new arteries may not be able to bring enough oxygen-rich blood to your heart.

In some cases, when plaque breaks, a blood clot may block the supply to your heart muscle. This causes a heart attack.

If a blood vessel to your brain is blocked, usually by a clot, you can have an ischemic stroke.

If a blood vessel in your brain bursts, you might have a hemorrhagic stroke. These are usually brought on by high blood pressure.

Studies have found that taking low-dose aspirin each day could help prevent heart attacks and strokes in some people who are 50 or older and at risk for heart disease. Talk with your doctor about whether you should take low-dose aspirin.

What Raises Your Risk for Coronary Artery Disease?

A number of things make you more likely to have coronary artery disease (risk factors). Some you can change, and some you can’t. They include:

  • Age, especially being older than 65
  • Being overweight or obese
  • Having diabetes, high blood pressure, or high cholesterol
  • A family history of heart disease, especially at a young age
  • Being male. Men have a greater risk of CAD until the risk evens out around age 70.
  • High stress in your life
  • Lack of physical activity (Check with your doctor first, but you should shoot for 30 minutes of exercise on most days of the week.)
  • Race. African Americans have a higher risk than others because they tend to have higher blood pressure. More obesity and diabetes in some Asian and Hispanic people can also raise risk.
  • Smoking or breathing secondhand smoke
  • Unhealthy eating, such as diets high in saturated fat, trans fat, processed foods, salt, and sugar

How Does Smoking Affect Coronary Heart Disease?

Smoking, whether your own or secondhand, raises your risk of getting CAD. That’s because chemicals in cigarette smoke can inflame the cells that line your blood vessels. This can make them narrower. It also may thicken blood so that it clots more easily.  

Talk to your doctor about getting help to quit smoking.

How Does High Cholesterol Affect Coronary Artery Disease?

Because cholesterol is part of what makes up the fatty deposits that collect in the damaged parts of your arteries, high cholesterol can worsen CAD quite a bit. But not all cholesterol numbers are created equal. You raise your risk for CAD if your LDL, or “bad cholesterol,” is high. And also if your HDL, or “good cholesterol,” is low.

Your doctor can test your cholesterol levels with  simple blood test.

What Is Ischemia?

Cardiac ischemia is when plaque and fatty matter narrow the inside of your artery so much that it can’t supply enough oxygen-rich blood to your heart. This can cause heart attacks, with or without chest pain and other symptoms.

Ischemia happens most during:

Coronary artery disease can get to a point where ischemia happens even when you’re resting. This is a medical emergency and may lead to a heart attack. If this happens to you, call your doctor or go to the emergency room. Ischemia can happen without warning in anyone with heart disease, although it’s more common in people with diabetes.

How Do You Diagnose Coronary Artery Disease?

Your doctor can tell if you have coronary artery disease after:

  • They learn your symptoms, medical history, and risk factors.

  • They do a physical exam.

You might also get diagnostic tests so your doctor can find the extent of your coronary artery disease and its effect on your heart. This helps them choose the best treatment for you. These tests include:

  • Cardiac catheterization and angiogram

  • Echocardiogram

  • Electrocardiogram (EKG)

  • Electron beam (ultrafast) CT scan

  • Exercise stress tests

How Do You Treat Coronary Artery Disease?

Your treatment may involve:

Lifestyle changes. If you smoke, quit. It’s a big risk factor for CAD. Your doctor may also talk to you about your diet -- less fat, salt, and sugar, and more vegetables, fruits, lean meats, and whole grains.

It also helps to keep your blood sugar in control if you have diabetes and exercise regularly (but talk to your doctor before starting an exercise program). Other things that might help include:

  • Avoid alcohol, or at least cut back.
  • Keep a healthy weight. (Talk to your doctor about the right weight for you).
  • Manage your stress.

MedicationsIf lifestyle changes aren’t enough, you might need medication. The drugs you’ll take depend on your situation. If you’ve been diagnosed with coronary artery disease, you could  take: 

  • Aspirin
  • Medications to help your cholesterol (statins, niacin, fibrates, and bile acid sequestrants)
  • Beta blockers
  • Calcium channel blockers
  • Ranolazine
  • Nitroglycerin
  • ACE inhibitors
  • Angiotensin II receptor blockers (ARBs)
  • Evolocumab (Repatha), which lowers the risk of heart attack and stroke in people with cardiovascular disease
  • Colchicine - 0.5 mg (or 0.6 mg) daily for those receiving other secondary preventive strategies

Surgery and other procedures. Common ones to treat coronary artery disease include:

All of these treatments boost blood supply to your heart, but they can’t cure coronary artery disease.

Doctors are also studying new ways to treat heart disease, including:

  • Angiogenesis. For this treatment, you’ll get stem cells and other genetic material through your vein or directly into your damaged heart tissue. It helps new blood vessels grow and go around the clogged ones.
  • Enhanced external counterpulsation (EECP). People who have long-term angina but haven’t gotten any help from nitrate medications or don’t qualify for some procedures may find relief with this. It’s an outpatient procedure -- one where you won’t need to be admitted to the hospital -- that uses cuffs on the legs that inflate and deflate to boost blood supply to your coronary arteries.

What Are Some Complications of Coronary Artery Disease?

Complications of coronary artery disease include:

  • Abnormal heart rhythm (arrhythmia): Your regular rhythm changes because of damage to heart muscle or a lack of blood supply. The most common form is called atrial fibrillation (AFib). An irregular heartbeat might lead to blood clots in your heart, and these can cause a stroke if they reach your brain.
  • Heart attack: Your coronary artery is totally blocked, keeping part of your heart muscle from getting enough oxygen. When blood flow to your heart muscle is blocked, your doctor might call it acute coronary syndrome.
  • Heart failure: Over time, CAD can weaken heart muscle and lead to heart failure, where your heart becomes too weak to supply your body with the blood it needs. This can be because your heart isn’t getting enough oxygen and nutrients or because it was damaged by a heart attack.  Arrhythmia, a common complication of CAD, also can cause heart failure or make it worse.

What’s Your Outlook With Coronary Artery Disease?

There’s no cure for CAD, but there are things you can do to help improve symptoms and keep it from getting worse. Your outlook depends in large part on the extent of your disease and what you can do to manage it. Quite a bit is still in your control.

An important part of recovering from CAD or other heart problems is cardiac rehabilitation (rehab). Research shows that it can lower your chance of death from heart disease and future heart problems. You’ll work with a team of people who will help you with:

  • Exercise and movement

  • Information about a healthy lifestyle, including food, medication, and other changes

  • Counseling to lower your stress and improve your mental health

What Should You Do in a Coronary Emergency?

It’s important to know your heart disease symptoms and what causes them.

Call your doctor if you feel new symptoms or if the ones you’re used to become more frequent or severe. Call 911 if you or someone you’re with has chest pain, especially when it comes with things like shortness of breath, heart palpitations, dizziness, a fast heartbeat, nausea, or sweating.

If you’re taking nitroglycerin for chest pain, call 911 if you’re still feeling pain after two doses (at 5-minute intervals) or after 15 minutes.

Emergency workers may tell you to chew an aspirin to help keep a blood clot from forming or getting larger.

Show Sources


Photo Credit: wildpixel / Getty Images

The American Heart Association: “Coronary Artery Disease - Coronary Heart Disease.”

The American Association of Family Physicians. ''Angiogenesis: Four Approaches to Restoring Cardiac Function.'' 

St. John Hospital Providence Health System: ''How EECP Works.''

Texas Heart Institute: “Are coronary artery disease, coronary heart disease, atherosclerotic heart disease and ischemic heart disease the same?”

Cleveland Clinic: “Coronary Artery Disease," “Coronary Artery Disease Symptoms.”

Mayo Clinic: “Coronary artery disease," “Cardiac rehabilitation.”

Medscape: “How do cholesterol levels affect the risk for coronary artery disease (CAD)?”

Merriam-Webster Dictionary: “Outpatient.”

Institute for Quality and Efficiency in Health Care: “Complications of coronary artery disease.”

American Heart Association: “Acute Coronary Syndrome.”

CDC: “Smoking and Cardiovascular Disease,” “Coronary Artery Disease (CAD).” “Coronary Artery Disease: Life Expectancy and Prognosis.” 

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