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What causes heart disease?

Medically reviewed by Neka Miller, PhD on December 14, 2020. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.


Estimates suggest that over 90 million adults in the United States have at least one form of heart disease (or cardiovascular disease). With heart conditions affecting that many people in the U.S., it’s natural to wonder, “What causes heart disease?”

Explore the answer to that question here—where you’ll find out how plaque deposits in the arteries can affect heart health, other factors that can contribute to the development of heart disease, and how a simple at-home blood test can help you find out more about potential heart disease risk factors.


Take the at-home Heart Health Test to measure indicators of cholesterol, blood sugar, and inflammation—all of which play key roles in heart disease risk.


A common cause of heart disease: plaque buildup

Coronary heart disease is used interchangeably with coronary artery disease to describe the same heart condition. The main cause of this type of heart disease is the buildup of plaque—which is made up of fatty deposits, cellular waste, and fibrin—on artery walls. This leads to hardened arteries, a condition known as atherosclerosis.

When plaque deposits become thick, artery walls start to narrow, blocking the effective flow of blood through the arteries. Obstructed blood flow due to this plaque buildup prevents blood from flowing evenly to the heart, preventing proper oxygen and nutrient supply. If arteries that carry blood back to the heart or to the brain are blocked by a sudden blood clot (thrombus) resulting from deposits of plaque, a heart attack or stroke can occur.

Atherosclerosis can start as early as childhood, but it usually does not become problematic until adulthood. Importantly, atherosclerosis is not a condition that affects only the elderly population. In some people, the condition can start in childhood and progress very quickly once they reach their 30s. Therefore, it is crucial to monitor your heart health on a regular basis (consider taking a heart health test to learn more about your potential risk factors for heart disease).

What contributes to the development of heart disease?

High blood pressure, high levels of “bad cholesterol,” and smoking are among the possible contributors to heart disease. Other health conditions, like diabetes and obesity, can also make heart disease more likely. These are all explored in more depth below.

1. High blood pressure

High blood pressure, also known as hypertension, is a major contributor to heart disease, heart attacks, and strokes. Blood pressure is a measure of pressure exerted by the blood that flows through arteries against the artery walls. Normally, blood pressure fluctuates throughout the day, but in people with hypertension, blood pressure is constantly elevated. Gradually, the artery walls become damaged from the high pressure, increasing their susceptibility to plaque buildup and atherosclerosis.

High blood pressure often has no warning signs or symptoms until an adverse cardiac event occurs, making it very dangerous if left untreated. Regular monitoring of blood pressure may help lower the risk of heart disease caused by high blood pressure.

2. High LDL cholesterol

Cholesterol is a waxy substance that’s involved in important cellular functions such as the synthesis of various hormones. This fat-like substance is also a major structural component of the cell membrane that keeps cells intact. At normal levels, cholesterol is good for you. But when levels of a specific kind of cholesterol—LDL cholesterol, or “bad cholesterol”—it can block artery walls, contributing to the progression of atherosclerosis and ultimately causing heart disease.

For this reason, LDL cholesterol levels are used as an indicator for an increased risk of heart disease. Some people are genetically predisposed to high LDL cholesterol, but often it is a result of a physically inactive lifestyle and/or a diet that’s high in saturated fat and trans fat.

3. Smoking

Smoking is one of the most major risk factors for heart disease. Smoking is known to damage artery walls, which are more vulnerable to atherosclerosis. Smokers also have a higher chance of blood clot formation. These conditions cause significant strain on the heart and thereby directly increase heart disease risk.

Other health conditions associated with heart disease

Diabetes, a health condition in which the body cannot effectively process blood sugar, can result in coronary heart disease. Diabetes causes thickening of blood vessels that leads to high blood pressure.

Obesity is another health condition that can result in high blood pressure and high cholesterol, due to the large amounts of triglycerides present in excess body fat. These factors can eventually contribute to the development of coronary heart disease.

Causes of other heart diseases

Coronary heart disease is not the sole type of heart disease. While atherosclerosis is the major cause of coronary artery disease, other heart disease types have distinct causes. Here is a look at various other kinds of heart disease and some of their contributing factors.

Congestive heart failure

This heart condition is caused by the inability of the heart to pump blood efficiently throughout the body. Also referred to as just heart failure, in this condition the heart muscle is too weak to supply all tissues and cells in the body with oxygen and nutrients, eventually leading to breathing problems and fatigue in the affected person. Congestive heart failure may be caused by coronary heart disease, diabetes, and/or high blood pressure.

Heart arrhythmia

Heart arrhythmia refers to an abnormal heartbeat. People with heart arrhythmia may have a heartbeat that is too fast (tachycardia), too slow (bradycardia), or irregular. Atrial fibrillation, a rapid heartbeat caused by erratic electrical impulses, is the most common type of heart arrhythmia.

Heart arrhythmia is associated with a history of heart attack, stress, and congenital heart defects. Certain medications can also cause an abnormal heartbeat.

Congenital heart disease

This type of heart problem is due to structural defects in the heart at birth. Such defects most commonly affect the heart walls, heart valves, arteries, and veins situated near the heart, causing inefficient blood flow from the heart to different parts of the body. Heart defects at birth can be caused by a combination of genetics and environmental factors. Family history plays a significant role in whether a child will be born with congenital heart disease, while exposure of a pregnant woman to certain substances (such as alcohol) within the first trimester of pregnancy can also contribute to this heart condition.

Heart valve disease

This type of heart condition blocks the proper opening or closing of heart valves, either preventing blood from flowing out of the heart properly or causing leakage (called regurgitation). Heart valve disease can be caused by congenital heart defects or other conditions that damage the heart valve—such as heart infections, rheumatic fever, high blood pressure, atherosclerosis, and heart failure. Age is also a contributing factor to heart valve disease because heart valves lose their normal shape and elasticity over time.

Rheumatic heart disease

Rheumatic heart disease is caused by damage to the heart valves from rheumatic fever. Heart and blood vessel inflammation are also present in this heart condition. Untreated infections with streptococcal bacteria, which commonly cause strep throat, are responsible for rheumatic heart disease. Due to the availability of antibiotics to treat strep infections, the incidence of rheumatic heart disease is less common today.

Heart infections

Heart infections can be caused by bacteria that enter the bloodstream through contaminated medical devices or cuts in the gums or skin that travel to the inner surface and valves of the heart. Serious heart infections are called infective endocarditis. Heart infections are more common in people with existing heart valve disease, and a cardiac infection can make the condition worse.

What can you do to prevent heart disease?

If you are at high risk for heart disease, incorporating certain lifestyle changes in your daily life may help you reduce your risk and allow you to continue living a full and healthy life. Cutting out sources of trans fat in your diet, engaging in regular physical activity, reducing alcohol consumption, quitting smoking, and managing other conditions that increase the risk of heart disease with proper medication are all possible changes that can help out your heart’s health.

Also, be sure to consult your healthcare provider for more personalized tips based on your own medical history.

How to test for heart disease risk factors

The Everlywell Heart Health Test kit can give you a good overall picture of your heart health. The test measures several different markers that can indicate a higher (or lower) risk of heart disease.

These markers include cholesterol, blood sugar (through HbA1c), and high-sensitivity C-reactive protein (or hs-CRP, a marker of inflammation). The blood sample can be easily collected at home with a simple finger prick, and you just send the sample to a lab for analysis before getting your secure, digital results (a prepaid shipping label is included with the kit for your convenience).


Signs of heart disease

Types of heart disease


References

1. Benjamin EJ, Blaha MJ, Chiuve SE, et al. Heart Disease and Stroke Statistics-2017 Update: A Report From the American Heart Association [published correction appears in Circulation. 2017 Mar 7;135(10 ):e646] [published correction appears in Circulation. 2017 Sep 5;136(10 ):e196]. Circulation. 2017;135(10):e146-e603. doi:10.1161/CIR.0000000000000485

2. Coronary artery disease. Mayo Clinic. URL. Accessed December 14, 2020.

3. Know Your Risk for Heart Disease. Centers for Disease Control and Prevention. URL. Accessed December 14, 2020.

4. Heart failure. Mayo Clinic. URL. Accessed December 14, 2020.

5. Heart arrhythmia. Mayo Clinic. URL. Accessed December 14, 2020.

6. Congenital heart defects in children. Mayo Clinic. URL. Accessed December 14, 2020.

7. Heart valve disease. Mayo Clinic. URL. Accessed December 14, 2020.

8. Rheumatic fever. Mayo Clinic. URL. Accessed December 14, 2020.

9. Staph infections. Mayo Clinic. URL. Accessed December 14, 2020.