Coronary artery disease (CAD) is a condition where the arteries supplying blood to your heart become narrowed or blocked by a buildup of fatty deposits called plaque. It’s the most common type of heart disease and a leading cause of death worldwide. Nearly half of adults in the United States have at least one of the three major risk factors: high blood pressure, high cholesterol, or smoking.
How Plaque Builds Up in Your Arteries
CAD starts with cholesterol. Specifically, LDL cholesterol (the “bad” kind) accumulates in the inner walls of your coronary arteries. Once lodged there, these fatty particles trigger inflammation. Your immune system sends white blood cells to deal with the problem, but those cells absorb the cholesterol and become bloated “foam cells” that pile up along the artery wall.
Over time, this process layers on more fat, dead cells, calcium, and scar tissue, forming what doctors call plaque. The artery wall thickens and stiffens. Blood flow to the heart muscle slows. This entire process, called atherosclerosis, typically unfolds over decades. Many people have significant plaque buildup without any symptoms at all.
The danger escalates when a plaque becomes unstable and ruptures. A blood clot forms at the rupture site, and if that clot is large enough to block the artery entirely, the result is a heart attack. Even plaques that don’t rupture can grow large enough to severely restrict blood flow, causing chest pain and other symptoms during physical activity.
Major Risk Factors
Having just one risk factor doubles your chances of developing heart disease. The three biggest are high blood pressure, high cholesterol, and smoking, and they’re all modifiable. Smoking directly damages blood vessel walls. High blood pressure forces your heart to work harder and accelerates artery damage. High cholesterol provides the raw material for plaque.
Beyond these three, several lifestyle factors play a significant role:
- Physical inactivity worsens cholesterol levels, blood pressure, blood sugar, and body weight.
- Unhealthy eating patterns heavy in saturated fats and refined carbohydrates (white bread, pasta, white rice) promote plaque buildup directly.
- Excess alcohol raises blood pressure and cholesterol. More than two drinks a day for men or one for women increases risk, and binge drinking is particularly harmful.
- Poor sleep including frequently waking throughout the night raises your risk of CAD.
- Chronic stress tightens arteries and often leads to behaviors like overeating or smoking that compound the problem.
Non-modifiable risk factors include age, family history, and being male (though women’s risk rises sharply after menopause). Diabetes is a particularly powerful risk factor that bridges both categories: it can’t always be prevented, but managing blood sugar significantly lowers heart risk.
What Coronary Artery Disease Feels Like
The hallmark symptom is angina, a pressure, tightness, or squeezing sensation in the chest. But angina comes in distinct forms, and knowing the differences matters.
Stable angina follows a predictable pattern. It shows up during physical exertion or emotional stress, lasts a few minutes, and goes away with rest. If you’ve had it for at least two months in a consistent pattern, it’s considered stable. Many people learn to anticipate it and manage it with medication.
Unstable angina is different and far more dangerous. It doesn’t follow a pattern. It can strike at rest, feel stronger or last longer than usual, and may not respond to rest or medication. Unstable angina is a medical emergency because it can progress to a heart attack.
A less common form called vasospastic angina (sometimes called variant angina) happens when the muscles in the artery wall suddenly tighten, temporarily narrowing the vessel. This type typically occurs at rest, often between midnight and early morning.
Not everyone with CAD experiences chest pain. Some people feel shortness of breath, fatigue, or pain in the jaw, neck, back, or arm. Women are more likely than men to have these “atypical” symptoms. In some cases, a heart attack is the first sign that CAD exists at all.
How CAD Is Diagnosed
Doctors use several tools to evaluate your coronary arteries, ranging from simple to highly detailed.
A coronary calcium scan is a quick CT scan that measures calcium deposits in your artery walls, a direct marker of plaque. The result is a number called a calcium score. A score of zero means no detectable calcium and suggests a low risk of heart attack. A score between 100 and 300 indicates moderate plaque and a relatively high risk of a heart attack within the next three to five years. Above 300 signals more extensive disease and higher risk.
CT angiography (CCTA) takes imaging a step further. A contrast dye is injected into a vein in your arm, and a CT scanner creates a detailed three-dimensional view of your coronary arteries. It doesn’t require a catheter, making it less invasive than traditional angiography. Current guidelines from the American Heart Association and American College of Cardiology recommend it as a first test for certain people with stable chest pain who haven’t been diagnosed with CAD, particularly when the likelihood of disease is uncertain.
Invasive coronary angiography remains the most detailed option. A thin tube is threaded through an artery in your leg or arm up to the heart, and dye is injected directly into the coronary arteries. This gives the clearest picture of blockage location and severity and is typically used when intervention (stent or surgery) is being considered.
Treatment Options
Treatment for CAD depends on how severe the blockages are, how many arteries are affected, and how well your heart is functioning overall.
Medications
Most people with CAD take cholesterol-lowering medication, typically a statin. The goal for people with established disease is to cut LDL cholesterol by at least 50% and get it below 70 mg/dL. For those at very high risk, the target drops further to below 55 mg/dL. If a statin alone doesn’t reach those levels, additional medications can be added to close the gap.
Beyond cholesterol drugs, common CAD medications include blood thinners to prevent clots, blood pressure medications to reduce strain on the heart, and drugs that help manage angina symptoms. The specific combination varies from person to person.
Stents and Bypass Surgery
When blockages are severe enough to limit blood flow or pose an immediate threat, two procedures can restore it. Percutaneous coronary intervention (PCI), commonly known as getting a stent, involves threading a catheter to the blocked artery and inflating a small balloon to open it, then leaving a tiny mesh tube in place to keep it open. Recovery is relatively quick, often just a few days.
Coronary artery bypass grafting (CABG) is open-heart surgery. A blood vessel from another part of your body is used to reroute blood around the blocked section. Recovery takes longer, typically six to twelve weeks. Bypass surgery is generally preferred for people with blockages in the left main artery, severe disease in three or more vessels, widespread diffuse disease, or significantly weakened heart muscle. People with diabetes who have multi-vessel disease also tend to do better with bypass than with stents.
Reducing Your Risk
Because CAD develops over decades, the earlier you address risk factors the more impact you can have. The most effective changes are also the most familiar: regular physical activity, a diet built around vegetables, fruits, whole grains, fish, and healthy fats, maintaining a healthy weight, not smoking, limiting alcohol, managing stress, and getting consistent sleep. These aren’t minor lifestyle tweaks. Physical inactivity alone worsens nearly every other risk factor for heart disease, from cholesterol to blood pressure to blood sugar.
If you already have risk factors, monitoring matters. Knowing your blood pressure, cholesterol numbers, and blood sugar gives you and your doctor a clear picture of where you stand and what to address first. For people with a family history or borderline risk, a coronary calcium scan can help clarify whether plaque has already started forming, often before symptoms appear.