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Heart Diseases/Coronary Artery Disease

What Causes Coronary Artery Disease? Understanding Atherosclerosis

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Written by

Team, Swasth Hriday

Published on

September 24, 2024

Coronary artery disease (CAD) is one of the leading causes of death worldwide, but many people don’t know its root cause: atherosclerosis. This condition involves the buildup of plaque inside your arteries, reducing blood flow to the heart. Over time, this can lead to serious complications like heart attacks and strokes.

In this blog, we will break down what atherosclerosis is, how it leads to coronary artery disease, and what you can do to lower your risk.

What is Coronary Artery Disease (CAD)?

Coronary artery disease (CAD) occurs when the arteries that supply blood to your heart muscle become narrowed or blocked by plaque. This restricts the flow of oxygen-rich blood, which the heart needs to function properly. CAD is the most common type of heart disease, and if left untreated, it can lead to angina (chest pain), heart attacks, or even heart failure.

Image Description: A visual representation of healthy arteries versus those affected by CAD, showing the narrowing caused by plaque buildup.

The Role of Atherosclerosis in CAD

The primary cause of CAD is atherosclerosis—the buildup of fatty deposits, known as plaque, on the walls of your arteries. Plaque is made up of cholesterol, calcium, fat, and other substances. Over time, plaque hardens and narrows the arteries, limiting blood flow to the heart.

How Atherosclerosis Develops:

  1. Plaque formation: Atherosclerosis begins when cholesterol and other fats start to build up inside the artery walls.
  2. Inflammation: The body responds to this buildup with inflammation, which leads to the thickening of artery walls.
  3. Narrowing of arteries: As plaque builds up, the arteries become narrower, making it difficult for blood to flow through.
  4. Reduced blood flow: Over time, reduced blood flow deprives the heart muscle of oxygen, which can cause angina or lead to a heart attack if the artery becomes completely blocked.

Reference: According to the American Heart Association, atherosclerosis is the most common cause of coronary artery disease and can begin in early childhood, developing over decades .

What Causes Atherosclerosis?

Atherosclerosis is influenced by several factors, many of which can be controlled. Here are the key causes:

1. High Cholesterol Levels

  • What It Is: Cholesterol is a fatty substance found in your blood. Your body needs some cholesterol to function, but too much low-density lipoprotein (LDL), or “bad” cholesterol, can lead to plaque buildup in your arteries.
  • How It Causes CAD: When LDL cholesterol levels are high, it sticks to artery walls, contributing to atherosclerosis. This narrows the arteries and reduces blood flow to the heart.
  • Indian Context: In India, the consumption of fried foods and high-fat diets can contribute to high cholesterol levels. 47% of cardiovascular deaths in India are related to high cholesterol levels, according to the Public Health Foundation of India (PHFI) .

2. Smoking

  • What It Is: Smoking damages the lining of your arteries, leading to inflammation and making it easier for plaque to build up.
  • How It Causes CAD: Smoking causes atherosclerosis by narrowing the arteries and reducing blood flow. Smokers are at a much higher risk of developing coronary artery disease than non-smokers.
  • Global Data: The World Health Organization (WHO) states that smoking increases the risk of heart disease by 2-4 times, making it one of the most significant preventable causes of CAD .

Image Description: A comparison showing a healthy artery and a smoker’s artery filled with plaque due to smoking-related damage.

3. High Blood Pressure (Hypertension)

  • What It Is: High blood pressure, or hypertension, puts extra strain on your arteries. Over time, this pressure damages the artery walls, making it easier for plaque to form.
  • How It Causes CAD: The constant force of high blood pressure accelerates atherosclerosis, leading to blockages that cause coronary artery disease.
  • Indian Context: In India, nearly 25% of adults suffer from high blood pressure, contributing significantly to the rise in heart disease, as reported by the Indian Council of Medical Research (ICMR) .

4. Diabetes

  • What It Is: Diabetes affects your body’s ability to regulate blood sugar levels. High blood sugar can damage your blood vessels over time, increasing your risk of heart disease.
  • How It Causes CAD: People with diabetes are more prone to atherosclerosis because high glucose levels damage the arteries, making it easier for plaque to build up and block blood flow.
  • Global and Indian Data: Adults with diabetes are 2-3 times more likely to develop cardiovascular disease. With over 77 million diabetics in India, this makes CAD a serious concern for the nation .

The Impact of Atherosclerosis on the Heart

As plaque builds up in the arteries over time, it can lead to severe complications:

  • Angina (chest pain): When the heart muscle doesn’t get enough oxygen due to narrowed arteries, it can cause chest pain.
  • Heart attack: If a plaque ruptures and forms a blood clot, it can completely block an artery, causing a heart attack. According to the World Heart Federation, heart attacks caused by atherosclerosis result in millions of deaths each year .
  • Heart failure: In severe cases, CAD can weaken the heart over time, leading to heart failure, where the heart is unable to pump enough blood to meet the body’s needs.

Image Description: An infographic showing how plaque buildup leads to angina, heart attacks, and potentially heart failure if left untreated.

How to Reduce Your Risk of Atherosclerosis and CAD

The good news is that many of the risk factors for atherosclerosis and CAD are preventable or manageable. Here are key steps to reduce your risk:

  1. Control Your Cholesterol Levels: Eating a heart-healthy diet rich in fruits, vegetables, whole grains, and healthy fats like those found in fish and nuts can help lower cholesterol. Regular check-ups and, if necessary, medications such as statins can also help manage high cholesterol.
  2. Quit Smoking: Quitting smoking is one of the best things you can do for your heart. Within a year of quitting, your risk of heart disease drops by 50%. Resources and support for quitting smoking are widely available.
  3. Manage High Blood Pressure: Regular monitoring of blood pressure and making lifestyle changes, such as reducing salt intake, can help keep your blood pressure in a healthy range. Medications may also be prescribed to control hypertension.
  4. Exercise Regularly: Regular physical activity helps keep your heart strong and your arteries healthy. The World Health Organization (WHO) recommends at least 150 minutes of moderate exercise per week to lower the risk of heart disease .
  5. Manage Diabetes: If you have diabetes, work with your healthcare provider to control your blood sugar levels. This will help reduce the damage to your arteries and lower your risk of developing CAD.

In Conclusion

Atherosclerosis is the primary cause of coronary artery disease (CAD), a condition that affects millions of people worldwide. By understanding the risk factors—like high cholesterol, smoking, hypertension, and diabetes—you can take active steps to prevent the buildup of plaque in your arteries.

Managing these risk factors through lifestyle changes, regular medical check-ups, and, when necessary, medication can significantly reduce your chances of developing CAD and improve your heart health.

Key Takeaways:

  • Coronary artery disease (CAD) is primarily caused by atherosclerosis, which is the buildup of plaque in the arteries.
  • Key causes of atherosclerosis include high cholesterol, smoking, high blood pressure, and diabetes.
  • Lifestyle changes such as quitting smoking, eating a healthy diet, exercising regularly, and managing blood pressure can significantly reduce your risk of CAD.
  • In India, rising rates of diabetes, high blood pressure, and high cholesterol are driving an increase in CAD cases.

Image Suggestions Recap:

1. A visual comparison of healthy arteries versus arteries affected by atherosclerosis.

2. A detailed infographic showing how plaque buildup from high cholesterol narrows the arteries.

3. A diagram showing how smoking damages arteries, leading to atherosclerosis.

4. An infographic explaining the process from atherosclerosis to heart attack and heart failure.

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