Coronary Heart Disease
Coronary Heart Disease

Coronary Heart Disease Causes and Risk Factors

What causes coronary heart disease?

Coronary heart disease may have more than one cause, including plaque buildup or problems that affect how the heart’s blood vessels work. Whatever the cause, taking steps to keep your heart and blood vessels healthy starting early in life can prevent risk factors from ever developing.

Plaque buildup


Plaque  buildup in the  arteries  is called atherosclerosis. When plaque builds up inside the arteries that supply blood to the heart muscle, those coronary arteries harden and become narrower over time. This can lower or block blood flow to the heart muscle, preventing the heart from getting enough oxygen-rich blood. This is the main cause of obstructive coronary artery disease.

Normal vs a blocked artery
Normal versus a blocked artery. The large image on the left shows the location of the coronary arteries in the heart. The top right image shows a healthy coronary artery with typical blood flow. The bottom right image shows a blocked coronary artery, narrowed by plaque buildup on the walls of the vessel. Medical Illustration Copyright © 2023 Nucleus Medical Media, All rights reserved.


Small amounts of plaque can also build up inside the small blood vessels in the heart, causing coronary microvascular disease.

Problems with how the blood vessels work

Problems with how the heart’s blood vessels work can cause coronary heart disease. For example, the blood vessels may not respond to signals that the heart needs more oxygen-rich blood. Usually, coronary arteries widen to allow more blood flow to the heart when a person is physically active or under stress. If you have coronary heart disease, the size of these arteries may not change, or they may even narrow.

The cause of these problems is not clear, but it may involve damage or injury to the walls of the arteries or tiny blood vessels from chronic  inflammation high blood pressure, or diabetes. All of these can cause blood vessels to narrow over time.

Damage to the inner walls of the larger coronary arteries can cause them to spasm (suddenly tighten). This is called vasospasm — the spasm causes the arteries to narrow temporarily and blocks blood flow to the heart.

Coronary microvascular disease in small arteries and obstructive coronary artery disease in large arteries
Coronary microvascular disease in small arteries and obstructive coronary artery disease in large arteries. Figure A shows the small coronary artery network, which includes a healthy artery and an artery with coronary microvascular disease. Figure B shows a large coronary artery with plaque buildup.

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What raises your risk of heart disease?

Your risk of coronary heart disease goes up based on the number of risk factors you have and how serious they are. Some risk factors — such as high blood pressure and high blood cholesterol — can be adjusted through heart-healthy lifestyle changes. Other risk factors, such as your age, sex, family history, and race and ethnicity, cannot be changed.


Genetic or lifestyle factors can cause plaque to build up in your arteries as you age. Age-related changes in the small blood vessels of the heart also raise the risk for coronary microvascular disease.

In men, the risk for coronary heart disease starts to increase substantially around age 45. Before menopause, women have a lower risk of coronary heart disease than men. After around age 55, the risk for women goes up. This is probably because of hormone changes after menopause.

Environment and occupation

Air pollution in the environment can put you at higher risk of coronary heart disease. The increase in risk may be higher in older adults, women, and people who have diabetes or obesity. Air pollution may cause or worsen other conditions that are known to increase your risk of coronary heart disease, such as high blood pressure and inflammation.

Your work can raise your risk if you:

  • Are exposed to toxins, radiation, or other hazards
  • Have a lot of stress at work
  • Sit for long periods
  • Work more than 55 hours a week or work long, irregular, or night shifts that affect your sleep

Family history and genetics

A family history of early heart disease is a risk factor for coronary heart disease. This is especially true if your father or brother was diagnosed before age 55 or if your mother or sister was diagnosed before age 65. Research shows that some  genes  are linked with a higher risk for coronary heart disease.

Lifestyle habits

Over time, unhealthy lifestyle habits can lead to plaque buildup in the heart’s blood vessels.

  • Being physically inactive can worsen other heart disease risk factors, such as high blood cholesterol and  triglyceride  levels, high blood pressure, diabetes and prediabetes, and overweight and obesity.
  • Not getting enough good-quality sleep, including waking up often throughout the night, may raise your risk of coronary heart disease. While you sleep, your heart does not work as hard as it does when you are awake. Waking up suddenly can cause a sharp increase in blood pressure and heart rate, which has been linked to angina (chest pain related to the heart) and heart attacks.
  • Smoking or long-term exposure to secondhand smoke can damage your blood vessels. 
  • Stress can cause your arteries to tighten. Stress may also indirectly raise your risk of coronary heart disease if it makes you more likely to smoke or overeat foods that are high in fat and added sugars.
  • Unhealthy eating patterns, including consuming high amounts of saturated fats and refined carbohydrates (such as white bread, pasta, and white rice), can lead to overweight and obesity, high blood cholesterol, atherosclerosis, and plaque buildup in the heart’s arteries.

Learn about steps you can take to lead a more heart-healthy lifestyle.

Other medical conditions

Other medical conditions affecting your heart and blood vessels can raise your risk of developing coronary heart disease, including:

Therapeutic Lifestyle Changes

The NHLBI Therapeutic Lifestyle Changes (TLC) Program aims to help people lower blood cholesterol numbers and improve heart health. The TLC Program’s step-by-step plan combines healthy food choices, physical activity, and weight management to lower the risks for heart disease, metabolic syndrome, and other serious medical conditions.

There are also several medical conditions that are not directly related to your heart and blood vessels that may increase your risk for coronary heart disease, such as:

Race or ethnicity

Heart disease is the leading cause of death for people of most racial and ethnic groups in the United States, including African Americans and white people.

For people who are Hispanic, Asian American or Pacific Islander, and American Indian or Alaska Native, heart disease is second only to cancer in causing death. People of South Asian ancestry have a higher risk of developing coronary heart disease and serious complications than others who are Asian American.


Coronary heart disease affects both men and women. Obstructive coronary artery disease is more common in men. However, nonobstructive coronary artery disease is more common in women. Since the nonobstructive type is harder to diagnose, women may not be diagnosed and treated as quickly as men are.

If you are a woman who has chest discomfort or shortness of breath during physical activity, ask your healthcare provider about tests to check for nonobstructive coronary artery disease or coronary microvascular disease. Learn about more conditions that increase risk for women.

How to prevent coronary heart disease

Coronary heart disease is largely preventable. Studies show that heart-healthy living — quitting smoking or never starting, eating healthy foods, and being physically active — throughout life can prevent or delay coronary heart disease and its complications in most people.

A heart-healthy lifestyle is important for people of all ages, but it is especially important for anyone who has other risk factors for heart disease. Work with your healthcare provider to set up a plan that works for you based on your lifestyle, your home and neighborhood environments, and your culture. This may mean taking steps to improve your diet, get physically active, manage other medical conditions, and help you quit smoking.

View tips for preventing heart disease.

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