Chapter 4 : Causes of Heart Disease

Heart disease is caused by a number of different factors. Learning about these potential causes and risk factors can help you determine if you are at risk for heart disease.

The most common type of heart disease in adults is coronary artery disease, often abbreviated as CAD. CAD is caused by atherosclerosis, which is a medical term for hardening of the arteries. What makes your arteries harden? Children’s arteries are generally clear, elastic and flexible, but as we get older, deposits of fat, cholesterol, calcium, blood clots and other junk builds up along the artery walls.

To get an idea of what this is like, think of the plumbing in an old house with hard water. Water flows through the pipes, but it leaves deposits of minerals behind. Eventually, the faucet will begin to take longer than usual to turn on, and the water that does come out will be copper-colored for a minute or so due to the minerals clogging the pipes. In this analogy, of course, the pipes represent your arteries. Blood flows through them, but it also leaves deposits behind.

Knowing this, the next logical question becomes “What causes plaque to build up in the first place?” Plaque builds up as a response to damage to the arterial walls. During the body’s natural healing process, plaque forms like a scar where arterial damage was located. Damage to the arterial walls can be caused by any one of the following:

Tobacco use

Bad news for those who smoke: smoking cigarettes doesn’t just affect your lungs and your teeth. It also increases your risk of heart disease.  The chemicals in cigarette smoke can damage the walls of your blood vessels, leading to atherosclerosis.

Even worse, nicotine increases blood clotting. Remember, blood clots often form where plaque breaks off of the artery wall, stopping up blood flow and causing a heart attack. Also, smoking increases your blood pressure and reduces the amount of oxygen that gets to your heart.

High Cholesterol

Cholesterol is a natural substance that your body uses to perform many essential functions, such as making cell membranes and manufacturing the bile acid that helps you digest fat. However, your body does not require very much cholesterol to perform these functions. Most of us are able to produce plenty of cholesterol on our own, and we also obtain it from our diets.

Cholesterol cannot move through our bodies under its own power. Instead, it hitches a ride on substances called lipoproteins. The type of lipoprotein that a molecule of cholesterol is attached to determines whether it is good cholesterol or bad cholesterol. High-density lipoproteins are the good guys. They carry HDL cholesterol, which actually cleans the walls of your arteries on its way back to the liver. Low-density lipoproteins are the bad guys. They carry LDL cholesterol, which smears across your artery walls and accumulates, particularly in areas that have been inflamed or damaged. High levels of LDL cholesterol have been associated with increased incidents of heart disease and heart attacks.

High Blood Pressure

High blood pressure can increase your risk of heart disease. When your blood pressure is too high, your heart is on overdrive all the time. Your heart is the one muscle in your body that never sleeps, so if it has to work harder than it should it can get damaged. Also, some arteries can become narrowed solely due to high blood pressure.


High levels of emotional stress have been shown to raise cholesterol levels and blood pressure. Also, some studies show that heart attacks increase after a severely stressful event, such as the death of a spouse or loved one. In addition, stress can also raise your adrenaline levels, which increases clotting. Of course, some stress can be beneficial and enjoyable, stimulating you to be more competitive at work and at play. This kind of stress is not implicated in heart disease. Also, even when it comes to bad stress, it’s not necessarily the stress itself that’s the problem. How you deal with stress is just as important. Try not to let it get under your skin.


Obesity is yet another factor that can contribute to the risk of developing both coronary artery disease and other heart diseases. This was illustrated in a recent study known as the Framingham Heart Study. In this study, participants were observed for a period of 14 years and monitored for a variety of different risk factors for heart disease. The result? Obesity increased the risk of heart failure by 104%! 

Another study, this one conducted by the University of Michigan, showed that participants who were considered obese developed coronary artery disease faster than participants with normal bodyweight, even when other risk factors were the same. Additionally, obesity is known to cause the wall of the left ventricle to become thickened so that it cannot pump as effectively. This can lead directly to heart failure.


Lack of enough physical activity is also a risk factor for heart disease. This is mainly because being a couch potato intensifies several other risk factors. For example, getting enough exercise helps keep you from becoming obese. Also, it can increase the levels of good cholesterol in your bloodstream and may inhibit the production of bad cholesterol. Additionally, it helps reduce stress. Regular exercise also has a beneficial effect on your cardiovascular system, training your heart to work harder with less effort.

In addition to being caused by any combination of the factors listed above, heart disease can also just happen as part of the normal aging process. However, it’s still important to take these risk factors into account. Not only do these factors increase your risk of heart disease, they also increase your risk of getting heart disease at a younger age. There is a world of difference between getting heart disease when you’re 100, and having a heart attack when you are only 45.

Heart Disease - Difference in Risk Based on Age, Sex, Gender and Race

One comforting fact about heart disease is that most of the factors that cause it are factors that you as an individual can exert some control over. However, there are two big risk factors that you can’t control - your demographic characteristics and your family history.

The word demographic means “a segment of the human population.” Demographics can involve several characteristics, including age, gender and race. Studies have shown that different demographics have different risks of heart disease.

So, who is at risk? As far as gender goes, men are the biggest losers here. Men have a greater risk of both developing and dying from heart disease at an earlier age than women. That’s not to imply that heart disease is not a serious problem for women as well . . . it definitely is! But, women’s death rate from heart disease does not start to exceed the male death rate from heart disease until after age 65. However, heart attacks are more likely to be misdiagnosed in women because they often have atypical symptoms - nausea, vomiting and fatigue instead of chest pain, for example.

Once a heart attack happens, women as a group have poorer survival rates and poorer outcomes. Some women’s rights groups say that the disparity is due primarily to women being under treated. That may be part of the problem, but no doubt part of the disparity results from women having heart attacks at a more advanced age then men.

As far as age goes, younger people have a lower risk of heart disease. For example, over 83% of deaths caused by heart disease happened in people over the age of 65. However, coronary artery disease is a long-term, progressive illness. Don’t feel invulnerable just because you are under 65. The habits you develop now can either cause heart disease in the future or help protect you from it.

Race is another demographic factor that can raise your risk of heart disease. For example, the American Heart Association estimates that approximately 40% of African Americans are afflicted with some form of heart disease. For Latinos, the figure is 25%. In recent years, heart disease has also become a serious problem among Native Americans. Historically speaking, it was almost unheard of in this population. However, it is now the leading cause of death in this group.

Nobody is quite sure what causes these variations. It could be a genetic variation that is widely shared among people with the same ethnicity. However, these variations could also be due to differences in diet, smoking habits and access to preventative healthcare.

Is It All in the Family?

You may have inherited your father’s eyes and your mother’s smile. But could you also have inherited their risk of heart disease? Fortunately or unfortunately, depending on your family history, there is also a genetic component to your risk of heart disease. For example, a study done by scientists at John Hopkins University in Baltimore, Maryland showed that siblings of people with heart disease show an increased risk of getting heart disease themselves over the next 10 years.

The increased risk was highest for males. Brothers who had a sibling develop any form of heart disease had a 10 percent greater than normal chance of developing heart disease themselves. For sisters, the increase in risk was 7 percent. Genetic factors appear to play a role in how your body manufactures cholesterol and how likely your arteries are to harden and develop plaque.

However, just because heart disease runs in the family doesn’t mean that you are doomed to experience it yourself. Instead, knowing that relatives suffer from heart disease can be seen as a warning that should lead you to look over your lifestyle for risk factors for heart disease. Even for people with a genetic component, there is usually a lifestyle factor as well. Bad heart genes increase the risk of heart disease developing in response to lifestyle factors such as diet and exercise. It’s possible to reduce or even cancel out the effect of genetics. You just have to be willing to take extra care of yourself. In the chapter on prevention, we will look at some strategies to help you do just that.

What about congenital heart defects? Once you’ve had one baby with a heart defect, you do have a higher than usual chance of having another baby with a similar problem. This is because some heart defects are inherited. However, many are not. If your child’s heart defect is not caused by genetics, you should be able to conceive again without any worries. Unfortunately, genetic science is still in its infancy. So, for some heart defects, a clear hereditary link has been established. However, for others, scientists simply are not sure.

The best way to find out about your risk of conceiving another child with a congenital heart defect is simply to talk with your doctor. He or she will be able to give you more information about your individual situation. Your doctor may also refer you to another specialist for genetic testing and counseling, if applicable.

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