What Causes Hardening of the Arteries?

Hardening of the arteries is another name for the medical condition, atherosclerosis, which occurs when cholesterol and other substances build up in the walls of arteries and form hard structures called plaques. Some level of hardening of the arteries is natural as we age, but unhealthy lifestyle habits can speed up the rate at which and the amount of hardening that occurs. This can increase your risk of heart attack and stroke. 

Causes

Cardiovascular disease is one of the leading causes of death in the world. It is characterized by chronic inflammation of the arterial inner wall. Our arteries are composed of three layers:

• The outer wall or adventitia
• The media or the middle muscular layer
• The intima or inner wall.

The early stages of hardening begin at the intima.

The formation of atherosclerotic plaques is a complex process related both to genetic factors and lifestyle choices. A particularly strong risk factor for hardening of the arteries is an elevated blood level of low density lipoproteins (LDL). At normal levels, LDL cholesterol can pass through the endothelial cell layer that makes up the intima, but at higher levels, some of the LDL particles can get stuck in the intima’s subendothelial layer. The trapped LDL undergoes a chemical reaction called oxidation, which is toxic to the cell wall causing an inflammatory response.

Monocytes—or white blood cells—that normally serve to attack foreign molecules in the body engulf the oxidized LDL particles creating a foam cell. Cytokines and other inflammatory markers form a fibrous cap around the injured area forming a plaque. If the plaque ruptures, tissue factors are released, which results in the formation of a thrombus or blood clot.

Reduced blood flow by the plaque-hardened artery is called arterial stenosis. The complete blockage of the artery is called a thrombotic occlusion. These two processes can lead to a cardiovascular event such as a heart attack or stroke.

Risk Factors

Genetic conditions such as familial hypercholesterolemia, which render the body unable to remove LDL from the blood, can increase your risk of or the rate at which your artery hardens. While the genetic factors that contribute to atherosclerosis are not well known, there are alterable risk factors that you should be aware of.

Major risk factors for atherosclerosis include:

• Unhealthy blood cholesterol levels: High LDL cholesterol or low HDL cholesterol.
• High blood pressure: Sustained high blood pressure over 140/90 mmHg for those without preexisting conditions and over 130/80 mmHg or higher for those with diabetes or kidney disease.
• Smoking: This can damage and tighten blood vessels, raise cholesterol levels, and raise blood pressure. Smoking also doesn't allow enough oxygen to reach the body's tissues.
• Insulin resistance: This worsens all other atherosclerosis risk factors including diabetes, high blood pressure, and unhealthy cholesterol levels.
• Diabetes: With this disease, the body's blood sugar level is too high because the body doesn't make enough insulin or doesn't use its insulin properly.
• Obesity: The extra weight is related to other health conditions.
• Sedentary lifestyle: A lack of physical activity or exercise puts you at higher risk of developing high blood pressure, diabetes, high blood cholesterol levels, and overweight or obesity thereby increasing your risk of atherosclerosis.
• Unhealthy diet: Foods that are high in saturated and trans fats, cholesterol, salt not only put you at risk of developing atherosclerosis but can also precipitate exacerbations of cardiovascular disease. 
• Older age: As you get older, your risk for atherosclerosis increases. We all develop some atherosclerosis as we age, but as you age lifestyle factors can worsen the condition. Quitting smoking, limiting alcohol, eating a balanced diet, and exercising can stop the impact of arteriosclerosis on our blood vessels.
• Family history of early heart disease: Your genes can paint a picture of what your heart health will look like in the future. Although having a close family member experience a heart attack does not mean that you will, you may want to consider getting tested for genetic conditions if there is a pattern in your family. 

Prevention

• While you can't reverse atherosclerosis, there are some lifestyle changes you can make to help slow the progression or help prevent it. These include:
• Avoiding fatty foods
• Adding fish to your diet twice per week
• Getting at least 75 minutes of vigorous exercise or 150 minutes of moderate exercise each week
• Quitting smoking if you’re a smoker
• Losing weight if you’re overweight or obese
• Managing stress
• Treating conditions associated with atherosclerosis, such as hypertension, high cholesterol, and diabetes

A Word From Verywell

Hardening of the arteries occurs without symptoms so the best way to be sure that it does not happen is to prevent it altogether by adopting a healthy lifestyle. Some atherosclerosis happens naturally with age, requiring you to take a statin. If you fall into this category try making some lifestyle changes. It is never too late to adopt heart-healthy habits like routine exercise, healthy eating, and quitting smoking, but the sooner, the better.