What causes arterial damage in adults with risk factors like hypertension, high cholesterol, or smoking?

What Damages Your Arteries

Atherosclerosis—the primary disease damaging your arteries—is caused by a combination of smoking, high cholesterol (especially elevated LDL), hypertension, and diabetes, with these risk factors working together to create inflammatory injury, lipid accumulation, and structural weakening of arterial walls. 1, 2

Primary Mechanisms of Arterial Damage

Atherosclerotic Process

• Atherosclerosis leads to gross thickening of the arterial inner layer (intima) with massive fibrosis, calcification, and accumulation of fatty acids. 1
• The integrity of the arterial wall becomes compromised when inflammatory cells degrade the structural matrix, leading to rupture at plaque edges. 1
• Intimal thickening increases the distance between the inner lining and the muscular middle layer (media), cutting off oxygen and nutrient supply, which causes smooth muscle cell death and weakening of elastic structures. 1
• This process increases vessel stiffness and vulnerability to shear stress, ultimately leading to aneurysm formation and arterial tears (dissections). 1

Inflammatory and Oxidative Injury

• Atherosclerosis is fundamentally an inflammatory reaction to oxidized LDL cholesterol within the arterial wall, with macrophages, T lymphocytes, and mast cells driving both development and progression to high-risk lesions. 2
• Excess oxidative and hemodynamic stress perpetuates plaque formation and can trigger rupture, resulting in acute thrombotic events like heart attacks and strokes. 3

Major Risk Factors That Damage Arteries

Hypertension (High Blood Pressure)

• Hypertension is the leading modifiable cardiovascular risk factor after smoking, found in 85% of patients with ruptured arterial aneurysms versus 52% with non-ruptured aneurysms. 1, 4
• High blood pressure accelerates atherosclerosis and vascular remodeling, directly impairing circulation. 4
• Among adults with hypertension, 49.5% are obese, and 41.7% have a 10-year coronary heart disease risk exceeding 20%. 4

Smoking

• Smoking shows the strongest association with arterial disease, with current smokers having an odds ratio of 2.6—the highest of any single risk factor for upper extremity arterial disease. 1
• Tobacco use (measured by thiocyanate concentration) correlates strongly with both severity and extent of atherosclerotic lesions in young adults who died accidentally. 1
• Smoking is the dominant risk factor for peripheral arterial disease, though less so for carotid disease. 1

High Cholesterol (Dyslipidemia)

• High total cholesterol and low HDL cholesterol are independently related to increased risk of arterial disease, with the total/HDL cholesterol ratio being the strongest lipid predictor. 1
• Elevated LDL cholesterol leads to endothelial dysfunction and arterial stiffness, contributing to increased blood pressure and further arterial damage. 5
• Approximately 63.2% of adults with hypertension also have high cholesterol, and their combined effect on cardiovascular risk is multiplicative rather than simply additive. 5

Diabetes Mellitus

• Diabetes increases the risk of ischemic stroke 2-5 fold and is strongly associated with atherosclerotic severity in pathological studies. 1
• Diabetes correlates with diffuse atherosclerosis, particularly in patients with end-stage renal disease. 1

Obesity

• Obesity creates a synergistic effect with hypertension that exceeds the sum of individual risk factors, with 35.7% of obese individuals having hypertension. 4
• Body mass index correlates positively with atherosclerotic lesion presence and extent in autopsy studies of young adults. 1
• Obesity is associated with insulin resistance, elevated triglycerides, reduced HDL cholesterol, and elevated blood pressure—a cluster known as metabolic syndrome. 1

Risk Factor Clustering and Cumulative Damage

• The presence of multiple risk factors is associated with striking acceleration of the atherosclerotic process, with both severity and extent increasing dramatically as the number of risk factors rises. 1
• Pathological studies show that as age and the number of risk factors increase, there is a striking increase in both severity and extent of atherosclerosis. 1
• The absence of risk factors is associated with virtual absence of advanced atherosclerotic lesions, even in older subjects. 1

Age as an Independent Factor

• Age independently predicts cardiovascular events more strongly than other individual traditional risk factors, reflecting the accumulation of atherosclerotic burden over decades. 6
• The risk slope becomes steepest beyond age 70 years, with age exerting strong independent prognostic effect even after adjusting for other risk factors. 6

Critical Clinical Pitfalls

• Do not assume arterial damage requires all risk factors to be present—even a single risk factor like smoking or hypertension can cause significant arterial injury over time. 1
• Recognize that 60% of patients with aortic aneurysms have cholesterol levels below 240 mg/dL, so "normal" cholesterol does not exclude significant arterial damage from other mechanisms. 1
• Understand that cumulative and excessive exposure to risk factors over time is required to overcome arterial defense mechanisms—this emphasizes the importance of early and sustained risk factor control. 7