Coronary artery disease affects millions of people worldwide, often developing silently over many years before symptoms appear. Understanding how this condition affects the heart, what increases your risk, and how to prevent or manage it can help you take meaningful steps toward protecting your heart health.
Understanding Coronary Artery Disease
Coronary artery disease is a condition that affects the arteries responsible for delivering oxygen-rich blood to your heart muscle. When you have this disease, the arteries that supply blood to the heart become narrowed or blocked. This happens because of a buildup of fatty deposits, cholesterol, calcium, and other substances that accumulate inside the artery walls. This buildup, called plaque, makes the arteries narrower and stiffer over time, which means less blood can flow through them to reach the heart.[1]
The disease is also sometimes called coronary heart disease or ischemic heart disease. When people talk about “heart disease” in general, they’re usually referring to coronary artery disease because it’s the most common type. The process that causes this disease, called atherosclerosis, means the gradual hardening and narrowing of arteries. While atherosclerosis can affect arteries anywhere in your body, when it affects the coronary arteries specifically, you have coronary artery disease.[2]
Think of your coronary arteries like traffic lanes leading to your heart. As plaque builds up, it’s similar to lanes gradually narrowing over time. Traffic still moves, just more slowly. However, if plaque suddenly ruptures, it can trigger a blood clot. This clot acts like a concrete barrier suddenly blocking the road completely. When blood can’t reach your heart, this causes a heart attack.[2]
How Common Is Coronary Artery Disease
Coronary artery disease stands as the leading cause of death in the United States and around the world. Over 18 million adults in the United States have this condition. To put this in perspective, that’s roughly the same as combining the populations of New York City, Los Angeles, Chicago, and Houston.[2]
About 1 in 20 adults aged 20 and older have coronary heart disease. In 2021, coronary artery disease killed 375,500 people in the United States. In 2022, it caused 371,506 deaths. Globally, the disease is responsible for approximately 7 million deaths annually and 129 million disability-adjusted life years lost, with the burden falling disproportionately on low- and middle-income countries.[3][7]
The disease affects both men and women, though patterns differ by age. In high-income countries, coronary artery disease accounts for about one-third of all deaths. The death rate increases with age and is generally higher for men than for women, particularly between ages 35 and 55. After age 55, the death rate for men declines, while the rate for women continues to climb. After age 70 to 75, the death rate for women becomes similar to that for men of the same age.[6]
Despite these sobering statistics, there is positive news. The cardiovascular disease mortality rate has declined 28% since 2003 because of advances in treatment, risk factor reduction, and prevention efforts. More people are living with coronary artery disease than ever before thanks to early detection and better treatments.[15]
What Causes Coronary Artery Disease
The primary cause of coronary artery disease is atherosclerosis, the gradual buildup of plaque inside artery walls. Plaque consists of cholesterol, waste products, calcium, and fibrin, which is a substance that helps your blood clot. As plaque collects along your artery walls, your arteries become narrow and stiff. The process of plaque buildup occurs over many years, even decades.[2]
The process begins when the inner lining of the artery walls becomes damaged. This damage can be caused by several factors, including high blood pressure, high cholesterol, smoking, and too much sugar in the blood from diabetes. Once the artery wall is damaged, cholesterol and fatty materials begin to deposit in the damaged area. Over time, calcium accumulates in the plaque, making it hard and further narrowing the artery.[1]
As plaque grows, it may bulge into the artery, narrowing the interior space and partially blocking blood flow. The blood supply becomes especially inadequate during physical exertion, when the heart muscle requires more blood. When your heart doesn’t receive enough blood due to any cause, this is called myocardial ischemia. If the heart doesn’t get enough blood, it can no longer contract and pump blood normally.[6]
Even a plaque that isn’t blocking very much blood flow can rupture suddenly. The rupture of plaque often triggers the formation of a blood clot. The clot further narrows or completely blocks the artery, causing acute myocardial ischemia. This acute blockage leads to what doctors call acute coronary syndromes, which include unstable angina and different types of heart attack.[6]
Risk Factors for Coronary Artery Disease
Several factors increase your risk of developing coronary artery disease. Some risk factors you cannot control, while others can be managed through lifestyle changes or medical treatment.
Risk factors you cannot change include your age, sex, and family history. Your risk increases if you’re a woman over age 55 or a man over age 45. If your father or brother had heart disease before age 55, or if your mother or sister had heart disease before age 65, your risk is higher. People who had a condition called preeclampsia during pregnancy also face increased risk.[23]
Risk factors you can influence include high cholesterol levels, high blood pressure, diabetes, smoking, obesity, an unhealthy diet, and physical inactivity. Having high cholesterol is a major contributing factor. When cholesterol levels in the blood are too high, more cholesterol deposits in artery walls. High blood pressure can damage blood vessel walls, making them more susceptible to plaque buildup. It also forces the heart to work harder.[4]
Smoking tobacco is especially dangerous because it damages and tightens blood vessels. It can cause high blood pressure while also restricting blood flow within your blood vessels. This combination makes smoking particularly hazardous for people with coronary artery disease. Being overweight or having obesity increases the workload on your heart and often occurs alongside other risk factors like high blood pressure, high cholesterol, and diabetes.[18]
Physical inactivity weakens the heart and makes other risk factors worse. A sedentary lifestyle contributes to weight gain and reduces the heart’s ability to function efficiently. An unhealthy diet high in saturated fats, trans fats, cholesterol, salt, and sugar promotes plaque buildup and can lead to obesity, high cholesterol, high blood pressure, and diabetes.[4]
Excessive alcohol consumption and poorly managed stress can also increase your risk. Regularly drinking too much alcohol can raise blood pressure and contribute to other health problems. Chronic stress may damage arteries and worsen other risk factors. Additionally, certain medical conditions like diabetes, high blood pressure, and high cholesterol directly damage blood vessels and accelerate atherosclerosis.[1]
Recognizing Symptoms of Coronary Artery Disease
You may have no symptoms of coronary artery disease for a long time. Plaque buildup takes many years, even decades. But as your arteries narrow, you may begin to notice mild symptoms. These symptoms indicate that your heart is pumping harder to deliver oxygen-rich blood to your body.[2]
The most common symptom is called stable angina. This is temporary chest pain or discomfort that comes and goes in a predictable pattern. You’ll usually notice it during physical activity or emotional distress. The pain may feel like pressure, squeezing, fullness, or discomfort in the center or left side of the chest. It typically goes away when you rest or take nitroglycerin, a medicine that treats angina.[2]
Some people experience shortness of breath, also called dyspnea, during light physical activity. Others may feel pain or discomfort in the upper body, including the arms, back, shoulders, neck, jaw, or upper stomach area above the belly button. Additional symptoms can include feeling sick to your stomach, feeling faint or lightheaded, or unusual tiredness.[4]
However, not everyone has the same symptoms, and some people may not have any symptoms before coronary artery disease is diagnosed. Many people don’t know they have the disease until they experience a heart attack. For about one in four people, the first symptom is sudden cardiac death.[3][9]
Symptoms of a heart attack include chest pain or discomfort that doesn’t go away, weakness, light-headedness, nausea, cold sweat, pain in the arms or shoulders, and shortness of breath. These symptoms can come on suddenly or develop slowly over hours or days. Not everyone who has a heart attack will have all these signs. If you experience these symptoms, call emergency services immediately.[4]
It’s important to talk to your doctor if you feel unusually tired for several days or develop any new health problems like pain or trouble breathing. Also discuss any existing health issues that are bothering you more than usual. If you’ve had a heart attack in the past, remember that symptoms of a new heart attack might be different from your last one.[23]
Preventing Coronary Artery Disease
You can reduce your risk of developing coronary artery disease by making heart-healthy lifestyle changes. Even if you already have the disease, these changes can help prevent it from getting worse and reduce your chances of serious complications like heart attacks.
Stopping smoking is one of the most important steps you can take. If you smoke, quitting provides immediate benefits. The risk of heart disease starts to drop in as little as a day after quitting. After a year without cigarettes, the risk drops to about half that of a smoker. Even if you’re not a smoker, avoid secondhand smoke, as it also damages blood vessels and increases risk.[19]
Eating a heart-healthy diet makes a significant difference. Choose foods rich in fruits, vegetables, and whole grains. Limit saturated fats, trans fats, cholesterol, sodium, and added sugars. Select lean proteins like chicken breast, fish, and low-fat dairy products. Your healthcare provider may recommend specific eating plans like the DASH diet or Therapeutic Lifestyle Changes Program designed to support heart health.[10]
Regular physical activity strengthens your heart and helps control other risk factors. Aim for at least 30 to 60 minutes of moderate-intensity aerobic activity, like brisk walking, most days of the week. If you haven’t been active for a while, start slowly and gradually increase your activity level. Always talk with your doctor before starting an exercise program, especially if you have heart disease or other health conditions.[19]
Maintaining a healthy weight reduces strain on your heart. If you’re overweight, losing even a small amount of weight can improve heart health. Weight loss often helps lower blood pressure, cholesterol, and blood sugar levels. Managing stress through relaxation techniques, meditation, or counseling can also benefit your heart.[10]
Regular health screenings help identify and control risk factors early. Have your blood pressure, cholesterol levels, and blood sugar checked regularly. If you have conditions like high blood pressure, high cholesterol, or diabetes, work with your healthcare team to manage them effectively through lifestyle changes and medications as needed.[23]
Limiting alcohol consumption is also important. If you drink alcohol, do so only in moderation. Getting enough quality sleep supports overall heart health. Adults should aim for seven to nine hours of sleep per night. Poor sleep is linked to increased risk of heart disease, high blood pressure, and other health problems.[10]
How Coronary Artery Disease Affects the Body
To understand how coronary artery disease affects your body, it helps to know how your heart normally works. Your heart is a muscular organ about the size of your fist that beats approximately 70 times per minute. It pumps about 2,000 gallons of blood through your body every day. Like any other tissue in your body, your heart muscle needs oxygen-rich blood to function properly.[5]
The heart receives its blood supply from the coronary arteries, which branch off from the aorta just after it leaves the heart. The right coronary artery and left coronary artery divide into smaller branches that spread across the surface of the heart, delivering blood to all parts of the heart muscle. These arteries ensure that every section of your heart receives the oxygen and nutrients it needs to keep pumping.[6]
When coronary artery disease develops, plaque buildup narrows these vital arteries. As the diameter of the artery decreases, less blood can flow through. Doctors classify the disease based on how much blockage exists. Obstructive coronary artery disease means the diameter of a large coronary artery is blocked by 50% or more. Nonobstructive coronary artery disease means the blood flow is blocked less than 50%. There’s also coronary microvascular disease, which affects the tiny arteries within the heart muscle itself.[3]
When blood flow to the heart is reduced, several things happen in your body. During rest, you might not notice problems because the narrowed arteries can still deliver enough blood for the heart’s basic needs. However, during physical activity or stress, your heart needs more oxygen. The narrowed arteries cannot deliver enough blood to meet this increased demand. This mismatch between oxygen supply and demand causes the chest pain known as angina.[6]
If a coronary artery becomes completely blocked by a blood clot, the section of heart muscle supplied by that artery is suddenly starved of oxygen. Without oxygen, heart muscle cells begin to die within minutes. This is a heart attack. The damaged heart muscle cannot pump as effectively, which reduces the amount of blood your heart can circulate to the rest of your body. Depending on which artery is blocked and how much heart muscle is affected, a heart attack can cause various levels of damage.[1]
Over time, chronic coronary artery disease can weaken the heart muscle. This may lead to heart failure, a serious condition where the heart can’t pump blood the way it should. When the heart doesn’t pump efficiently, fluid can back up in the lungs, causing shortness of breath, or in the legs, causing swelling. Coronary artery disease can also trigger irregular heartbeats called arrhythmias, which can be dangerous if severe.[4]
The reduced blood flow affects not just the heart but potentially your whole body. When your heart can’t pump enough blood, other organs may not receive adequate oxygen and nutrients. This can cause fatigue, difficulty concentrating, and reduced ability to perform physical activities. In severe cases, inadequate blood flow can damage other organs, including the kidneys and brain.[2]
