CAD stands for coronary artery disease, the most common type of heart disease in the United States. It develops when fatty deposits called plaque build up inside the arteries that supply blood to your heart, gradually narrowing them and restricting blood flow. About 1 in 20 adults age 20 and older have CAD, and it killed more than 371,000 Americans in 2022 alone.
How Plaque Builds Up in Your Arteries
CAD starts with damage to the inner lining of a coronary artery. When that lining is injured, immune cells rush to the area and begin absorbing cholesterol particles, particularly the “bad” LDL cholesterol circulating in your blood. These cholesterol-stuffed cells, called foam cells, collect beneath the artery wall and form what’s known as a fatty streak. Over time, more immune cells and muscle cells pile on, taking up even more cholesterol and forming a visible plaque.
If no further damage occurs, the plaque stabilizes. A tough fibrous cap forms over it, and the deposit gradually hardens with calcium. But the plaque keeps narrowing the artery. Once it blocks about 70% of the opening, blood flow becomes insufficient during physical effort or stress, which is when chest pain (angina) typically begins. At 90% blockage, symptoms can appear even at rest.
The more dangerous scenario happens when a plaque ruptures. Unstable plaques with thin caps and tiny calcium deposits are especially prone to breaking open. When they do, a blood clot forms rapidly at the site and can partially or completely block the artery. This is what causes a heart attack.
What CAD Feels Like
Chest pain is the most recognized symptom, occurring in about 92% of people experiencing an acute coronary event. It’s typically a squeezing, tightness, or heaviness behind the breastbone that gets worse with exertion or stress and eases with rest. The pain often radiates to the left jaw, shoulder, or arm.
Not everyone gets that classic presentation, though. Some people experience neck pain, back pain, throat discomfort, or even hiccups. Jaw or facial pain can be the only symptom in up to 6% of heart attack cases. Digestive symptoms like upper abdominal pain and indigestion are also possible, along with shortness of breath, dizziness, unusual fatigue, and fainting.
These atypical symptoms show up more often in women, older adults, and people with diabetes. Diabetes can damage the nerves that carry pain signals from the heart, which is why some diabetic patients feel little or no chest pain during a cardiac event. If you fall into any of these groups and experience unexplained fatigue, breathlessness, or dizziness alongside risk factors like high blood pressure or high cholesterol, those symptoms deserve attention.
Major Risk Factors
The four biggest drivers of CAD are smoking, high blood pressure, high cholesterol, and diabetes. Your LDL cholesterol ideally should stay below 100 mg/dL. For people at the highest risk of heart attacks, the target drops to below 70 mg/dL. Levels above 130 mg/dL are considered elevated enough to warrant intervention in most people.
Other factors that raise your risk include obesity, physical inactivity, a diet high in processed foods and added sugars, and a family history of early heart disease. Heavy alcohol use and chronic stress also contribute. Many of these risks compound each other: having both diabetes and high blood pressure, for example, is far worse than having either one alone.
How CAD Is Diagnosed
If your doctor suspects CAD, several tests can confirm it and measure its severity. A coronary calcium scan uses a CT scanner to measure calcium deposits in your artery walls, giving an early indication of plaque buildup. This test is also used to assess risk in people who smoke or don’t yet have symptoms. A coronary CT angiography goes a step further, using contrast dye and X-rays to create detailed images of blood flow through the coronary arteries.
If these less invasive tests suggest significant disease, the next step is typically invasive coronary angiography. A thin catheter is threaded into your coronary arteries and contrast dye is injected so doctors can see exactly where and how severe the blockages are. This test also serves as the gateway to treatment: if a blockage is found, it can sometimes be treated during the same procedure.
Treatment Options
Medications
Most people with CAD take some combination of medications to manage symptoms and reduce the risk of a heart attack. Nitrates, most commonly nitroglycerin, relieve chest pain by lowering blood pressure and widening arteries. Beta-blockers slow the heart rate so the heart doesn’t have to work as hard, which both prevents angina and limits damage if a heart attack occurs. Calcium channel blockers lower blood pressure and, in some forms, also slow the heart rate.
Cholesterol-lowering medications are a cornerstone of CAD management. High-intensity versions of these drugs can lower LDL cholesterol by 50% or more. For people who have already had a heart attack or acute coronary event, dual blood-thinning therapy with low-dose aspirin (75 to 100 mg daily) and a second antiplatelet drug is typically recommended for at least 12 months.
Procedures
When medications aren’t enough, two main procedures can restore blood flow. Percutaneous coronary intervention (commonly called stenting) involves threading a tiny mesh tube into the blocked artery to hold it open. It’s effective for single-vessel or less complex disease. Coronary artery bypass surgery reroutes blood around blocked arteries using vessels taken from elsewhere in the body. Bypass is generally preferred for people with blockages in the left main artery, severe disease in three or more vessels, significantly weakened heart muscle, or diabetes.
One important distinction: stenting requires repeat procedures significantly more often than bypass surgery. In studies of single-vessel disease, about 38% of patients who had stenting needed another intervention over several years of follow-up, compared to 12% of bypass patients. However, rates of death and heart attack were similar between the two approaches for single-vessel disease.
What Happens if CAD Goes Untreated
Left unchecked, CAD progresses. The most immediate danger is a heart attack, which occurs when a plaque ruptures and a clot cuts off blood supply to part of the heart muscle. A heart attack can leave permanent scar tissue that disrupts the heart’s electrical system, causing irregular rhythms called arrhythmias. Some of these, particularly ventricular tachycardia, can cause sudden cardiac death months or even years after the initial heart attack.
Over time, chronically reduced blood flow weakens the heart muscle itself, leading to heart failure. The heart can no longer pump blood efficiently, causing fatigue, fluid retention, and shortness of breath. Arrhythmias and heart failure often feed into each other: irregular rhythms reduce pumping strength, which worsens heart failure, which in turn makes arrhythmias more likely.
Lifestyle Changes That Slow Progression
Diet and exercise are not just preventive measures. They remain central to treatment even after a CAD diagnosis. The American Heart Association recommends a dietary pattern built around fruits, vegetables, whole grains, plant-based proteins like legumes and nuts, fish, and liquid vegetable oils such as olive or canola oil. Minimally processed foods, limited added sugar, low salt intake, and little to no alcohol round out the guidelines.
For physical activity, the target is at least 150 minutes of moderate exercise per week (like brisk walking) or 75 minutes of vigorous exercise (like jogging or cycling), spread across multiple days rather than crammed into a weekend. Regular activity helps maintain a healthy weight, improves cholesterol and blood pressure, and strengthens the cardiovascular system overall. For someone already living with CAD, these changes work alongside medications to slow plaque growth and reduce the odds of a cardiac event.