Heart disease is the number one cause of death both worldwide and in the United States. Specifically, ischemic heart disease (the type caused by blocked arteries supplying the heart) kills about 9.1 million people globally each year, accounting for 13% of all deaths. In the U.S., heart disease claimed 683,491 lives in the most recent annual data from the CDC.
That number has been climbing. Since 2000, annual deaths from ischemic heart disease have risen by 2.7 million worldwide, even as mortality rates per person have gradually improved. The gap reflects population growth and aging: more people are living long enough for heart disease to catch up with them.
How Heart Disease Kills
The process behind most heart disease deaths starts decades before any symptoms appear. It begins with inflammation inside the walls of your arteries. When you have high blood pressure, high cholesterol, high blood sugar, or you smoke, the inner lining of your arteries becomes damaged. White blood cells stick to these damaged spots and burrow into the artery wall, triggering a slow buildup of fatty material, calcium, and scar tissue known as plaque.
For most of its life, plaque grows outward rather than inward, so it doesn’t necessarily narrow the artery or cause symptoms. This is why many people with significant plaque buildup feel perfectly fine. The danger comes when a plaque ruptures. The cap covering the fatty deposit cracks open, exposing the material inside to your bloodstream. Your body treats this like an open wound: platelets rush to the site, a blood clot forms rapidly, and the artery can become completely blocked within minutes. When that artery feeds your heart muscle, the result is a heart attack.
Autopsy studies show that the plaques most likely to rupture aren’t necessarily the ones causing the most blockage. They tend to have large pools of fatty material and thin, fragile caps. This is one reason heart attacks can strike people who had no prior warning signs or who recently passed a stress test.
The Three Biggest Risk Factors
The CDC identifies high blood pressure, high cholesterol, and smoking as the key modifiable risk factors for heart disease. Each one damages arteries in a different way, and having more than one compounds the risk significantly.
High blood pressure forces your heart to work harder and puts constant mechanical stress on artery walls, accelerating the inflammatory process that leads to plaque. High cholesterol provides the raw material: when there’s more cholesterol circulating than your body can use, the excess deposits into artery walls. Smoking damages arteries through two mechanisms at once. Nicotine raises blood pressure, while carbon monoxide in cigarette smoke reduces the oxygen your blood can carry, forcing your heart to pump harder for less return.
Other important risk factors include diabetes, obesity, physical inactivity, and a diet high in processed foods. Family history also plays a role you can’t change, but the majority of heart disease risk comes from factors you can modify.
Who It Affects
Heart disease is the leading cause of death for men and women across most racial and ethnic groups in the United States, including Black, Hispanic, White, American Indian, and Alaska Native populations. For Asian American women, Pacific Islander women, American Indian and Alaska Native women, and Hispanic women, cancer edges out heart disease for the top spot, but heart disease remains the second leading cause.
Age matters too. In younger adults, unintentional injuries and cancer tend to top the list. Heart disease typically becomes the dominant killer starting in middle age, as the cumulative damage from decades of risk factor exposure reaches a tipping point. But plaque buildup begins much earlier. Studies of young adults have found early-stage arterial changes in people in their 20s and 30s, which is why prevention efforts focused on diet, exercise, and blood pressure control are most effective when started early.
How It Compares to Other Causes
Globally, the top causes of death after ischemic heart disease are stroke (the third leading cause, responsible for about 10% of deaths) and chronic obstructive pulmonary disease (fourth, at about 5%). COVID-19 emerged as the second leading cause of death in 2021 WHO data, bumping stroke and lung disease down one position each from their 2019 rankings. The top two categories overall are cardiovascular diseases (heart attacks and strokes) and respiratory conditions.
Heart disease’s dominance is a relatively modern phenomenon tied to longer lifespans and lifestyle changes. In lower-income countries, infectious diseases still claim a larger share of deaths, but as nations develop and life expectancy rises, heart disease climbs the rankings. It has held the number one position globally for over two decades.
Warning Signs of a Heart Attack
Because ischemic heart disease most commonly kills through heart attacks, recognizing the symptoms can be lifesaving. The classic warning signs include:
- Chest discomfort in the center or left side that lasts more than a few minutes, or goes away and comes back. It can feel like pressure, squeezing, or fullness rather than sharp pain.
- Pain radiating to the arms, shoulders, jaw, neck, or back.
- Shortness of breath, which can appear with or even before chest discomfort.
- Cold sweat, lightheadedness, or feeling faint.
- Unusual fatigue or nausea, symptoms more commonly reported by women.
Not everyone experiences the dramatic chest-clutching moment you see in movies. Women in particular are more likely to have subtler symptoms like unexplained tiredness, nausea, or back and jaw pain. If you or someone around you has these symptoms, calling 911 immediately gives the best chance of survival. Every minute a blocked artery goes untreated, more heart muscle dies.