Heart disease is a group of conditions that affect the heart’s structure or function. It includes coronary artery disease, heart failure, abnormal heart rhythms, and heart valve problems. Cardiovascular disease, a term often used interchangeably, is actually broader and covers diseases of all blood vessels in the body, not just the heart itself. Heart disease is the leading cause of death globally, responsible for a significant share of the estimated 17.9 million cardiovascular deaths each year.
The Most Common Types
Coronary artery disease is by far the most common form of heart disease in the United States. It develops when the arteries that supply blood to the heart become narrowed or blocked, reducing blood flow. If that blood flow drops enough, the result is a heart attack.
Heart failure means the heart can no longer pump blood efficiently enough to meet the body’s needs. It doesn’t mean the heart has stopped; it means it’s weakened or stiffened to the point where fluid can back up into the lungs and other tissues, causing fatigue and shortness of breath.
Arrhythmias are problems with the heart’s electrical system. The heart may beat too fast, too slow, or irregularly. Some arrhythmias are harmless, while others, like ventricular fibrillation, can be life-threatening within minutes.
Heart valve disease occurs when one or more of the heart’s four valves don’t open or close properly. A valve may leak (letting blood flow backward) or become stiff and narrow (restricting flow). Both problems force the heart to work harder over time.
Some heart conditions are present from birth. Congenital heart defects affect how blood flows through the heart and out to the body. These structural problems form during fetal development and range from minor issues that never need treatment to serious defects requiring surgery in infancy. The conditions most people think of when they hear “heart disease,” though, are acquired over a lifetime through a combination of genetics, aging, and lifestyle.
How Plaque Builds Up in Arteries
The process behind coronary artery disease is called atherosclerosis. It starts when the inner lining of an artery becomes damaged, often by high blood pressure, high cholesterol, or chemicals from cigarette smoke. Once damaged, that lining becomes a landing zone for fats, cholesterol, and calcium circulating in the blood. Over years, these substances accumulate into a deposit called plaque.
As plaque grows, the artery narrows. Less blood reaches the heart muscle, especially during physical exertion when the heart needs more oxygen. The buildup tends to concentrate at branch points in the arteries, where blood flow naturally creates more turbulence and stress on vessel walls. Risk factors like high blood pressure, smoking, and diabetes accelerate the process by increasing oxidative stress, which triggers inflammation and makes the artery walls even more receptive to plaque formation.
The real danger comes when a plaque deposit ruptures. A blood clot forms at the rupture site and can suddenly block the artery entirely. That’s a heart attack.
Heart Attack vs. Cardiac Arrest
These two terms describe different emergencies. A heart attack is a circulation problem: a blocked artery cuts off blood to part of the heart muscle, and that tissue begins to die if the blockage isn’t cleared quickly. The person is typically conscious, often experiencing chest pain or pressure.
Sudden cardiac arrest is an electrical problem. The heart’s rhythm becomes so chaotic that it stops pumping altogether. The person loses consciousness and has no pulse. Without CPR and defibrillation within minutes, it’s fatal. A heart attack can trigger cardiac arrest, but many heart attacks don’t lead to it, and cardiac arrest can also result from other conditions like cardiomyopathy, congenital defects, or infections that disrupt the heart’s electrical system.
Risk Factors You Can and Can’t Control
Age, sex, and family history all raise your risk, and you can’t change those. Heart disease risk climbs as you get older, and having a parent or sibling who developed it early is a meaningful warning sign, both because of shared genetics and because families often share diets, activity levels, and other habits.
The modifiable risk factors carry more weight in practice, because addressing even a few of them substantially lowers your odds:
- High blood pressure forces the heart to work harder and damages artery walls over time.
- High cholesterol feeds plaque formation. Excess cholesterol that your body can’t use builds up inside artery walls.
- Smoking damages blood vessels directly. Nicotine raises blood pressure, and carbon monoxide in cigarette smoke reduces the oxygen your blood can carry. Even secondhand smoke raises risk.
- Diabetes significantly increases the chance of dying from heart disease compared to people without diabetes.
- Obesity raises “bad” cholesterol and triglycerides while lowering “good” cholesterol. It also contributes to high blood pressure and diabetes.
- Physical inactivity is a risk factor on its own and makes several others worse, including blood pressure, cholesterol, weight, and blood sugar.
- Diet high in saturated fats, trans fats, and sodium directly promotes atherosclerosis and high blood pressure.
- Excessive alcohol raises blood pressure and triglyceride levels. General guidance is no more than one drink a day for women and two for men.
Symptoms Differ Between Men and Women
The classic heart attack warning, crushing chest pain, is real but not universal. Men report chest pain as their primary symptom about 13 to 15 percent more often than women do. Women are more likely to experience nausea, vomiting, dizziness, shortness of breath, and jaw or neck pain. Upper back pain, left shoulder pain, and abdominal discomfort also appear more frequently in women.
Women are also more likely to have warning signs in the days before a heart attack, particularly unusual fatigue. Because these symptoms don’t match the stereotypical picture, women’s heart attacks are more often missed or dismissed, both by patients themselves and by those around them. Shortness of breath and signs of fluid buildup in the lungs are especially common physical findings in women during a heart attack.
How Heart Disease Is Diagnosed
Diagnosis usually starts with blood tests. Some check cholesterol and blood sugar levels to assess ongoing risk. Others look for specific proteins that leak into the bloodstream when heart muscle has been damaged, which helps confirm or rule out a heart attack. A high-sensitivity C-reactive protein test can detect inflammation in the arteries, an early sign of trouble.
An electrocardiogram (ECG) is a quick, painless test that records the heart’s electrical activity. It reveals whether the heart is beating too fast, too slow, or irregularly. When rhythm problems come and go, a Holter monitor (a portable ECG device worn for a day or more) can catch irregularities that a brief office test would miss.
An echocardiogram uses sound waves to create moving images of the heart, showing how blood flows through the chambers and valves. It’s the go-to test for evaluating valve problems and overall pumping strength. Stress tests involve walking on a treadmill or riding a stationary bike while the heart is monitored, revealing how it responds to exertion and whether symptoms like chest pain or abnormal rhythms appear with exercise.
For a more detailed look at blockages, cardiac catheterization threads a thin tube through a blood vessel in the wrist or groin up to the heart. Dye injected through the tube makes the coronary arteries visible on X-ray, pinpointing exactly where and how severe any narrowing is. A chest X-ray, while simpler, can show whether the heart is enlarged or if fluid is building up in the lungs.
Reducing Your Risk
The prevention targets are concrete. Adults should aim for at least 150 minutes per week of moderate-intensity physical activity (like brisk walking) or 75 minutes of vigorous activity (like running or cycling). Blood pressure should generally stay below 130/80 mm Hg. For people whose levels are mildly elevated, lifestyle changes alone, such as reducing sodium, exercising, losing weight, and limiting alcohol, can bring blood pressure into range. Others will need medication in addition.
Diet changes that reduce saturated fat, trans fat, and sodium while increasing fruits, vegetables, and whole grains slow atherosclerosis and improve cholesterol numbers. Quitting smoking produces measurable cardiovascular benefits within weeks, and the risk continues to drop for years afterward. For people with diabetes, keeping blood sugar well controlled reduces the strain on blood vessels and the heart. None of these changes work in isolation the way they work together. Combining even modest improvements across several risk factors has a compounding protective effect.