Coronary Heart Disease Causes and Risk Factors

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Coronary heart disease may have more than one cause, including plaque buildup or problems that affect how the heart’s blood vessels work. How the Heart Works has more information about the heart and blood vessels.

Plaque buildup

plaque buildup in the arteries is called atherosclerosis. When this buildup happens in the heart's arteries over many years, the arteries become narrower and harden, reducing oxygen-rich blood flow to the heart. This is the main cause of obstructive coronary artery disease.

Small amounts of plaque can also develop in 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 of coronary heart disease. For example, the blood vessels may not respond to signals that the heart needs more oxygen-rich blood. Normally, the blood vessels widen to allow more blood flow when a person is physically active or under stress. If you have coronary heart disease, the size of these blood vessels may not change, or the blood vessels may even narrow.

The cause of these problems is not fully 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 which 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.

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 changed through heart-healthy lifestyle changes. Other risk factors, such as your sex, older age, family history, and race and ethnicity, cannot be changed.

Age

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

In men, the risk for coronary heart disease starts to increase 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 likely because women have less estrogen (a female hormone) 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 atherosclerosis and high blood pressure.

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 increase your risk of coronary heart disease because they 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 blood pressure and heart rate fall. Your heart does not work as hard as it does when you are awake. As you begin to wake up, your blood pressure and heart rate increase to the same levels as when you are awake and relaxed. Waking up suddenly can cause a sharp increase in blood pressure and heart rate, which has been linked to chest pain related to the heart called angina and heart attacks. Learn more about How Sleep Works.
• Smoking or long-term exposure to secondhand smoke can damage the 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 high in fat and added sugars.
• Unhealthy eating patterns include 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 improve your heart health in Heart-Healthy Living.

Other medical conditions

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

• Atherosclerosis
• Congenital coronary artery defects (heart problems you are born with)
• High blood LDL cholesterol (sometimes called “bad cholesterol”)
• High blood pressure
• High blood triglycerides

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:

• autoimmune and inflammatory diseases, such as Crohn’s disease, ulcerative colitis, psoriasis, lichen planus, pemphigus, histiocytosis, lupus erythematosus, and rheumatoid arthritis
• Chronic kidney disease
• Diabetes
• HIV/AIDS, especially among older adults. Part of the risk might be due to side effects of HIV treatments.
• Mental health conditions, including anxiety, depression, and post-traumatic stress disorder (PTSD)
• Metabolic syndrome
• Overweight and obesity
• Sleep disorders, such as sleep apnea or sleep deprivation and deficiency

Race or ethnicity

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

For Hispanics, Asian Americans or Pacific Islanders, and American Indians or Alaska Natives, heart disease is second only to cancer. People of South Asian ancestry are at higher risk of developing coronary heart disease and serious complications than other Asian Americans.

Sex

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

If you are a woman having chest discomfort or shortness of breath during physical activity, ask your doctor about tests to check for non-obstructive coronary artery disease or coronary microvascular disease. Learn about more conditions that increase risk for women.

Coronary heart disease is largely preventable. Studies show that heart-healthy living — never smoking or quitting smoking if you do smoke, eating healthy, and being physically active — throughout life can prevent coronary heart disease and its complications.

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.

Need more help to get started? Check out these tips for preventing heart disease from The Heart Truth®.