The term “athero” originates from Greek, meaning “gruel” or “paste,” describing the fatty deposits found within arteries. This forms the basis of atherosclerosis, a medical condition defined by the hardening and narrowing of arteries due to plaque buildup. This progressive disease is a major cause of various cardiovascular diseases, impacting blood flow throughout the body. Understanding this condition is important for overall health.
The Process of Plaque Formation
Atherosclerosis begins with damage to the endothelium, the inner lining of an artery. This injury allows low-density lipoprotein (LDL) cholesterol particles to infiltrate the artery wall.
The body’s immune system responds with inflammation. Monocytes, a type of white blood cell, migrate to the damaged site and transform into macrophages. These macrophages consume LDL cholesterol, becoming engorged and taking on a foamy appearance, earning them the name “foam cells.”
Foam cells, along with smooth muscle cells and other cellular debris, accumulate to form an atherosclerotic plaque. This deposit has a soft, fatty core and is covered by a fibrous cap. The process gradually narrows the artery, impeding blood flow.
Causes and Risk Factors
Plaque formation is influenced by modifiable and non-modifiable factors. Modifiable risk factors are those individuals can influence through lifestyle or medical intervention. High levels of LDL cholesterol, often called “bad” cholesterol, contribute to plaque development by readily entering damaged artery walls.
High blood pressure, or hypertension, places increased stress on arterial walls, leading to endothelial damage and promoting the disease process. Smoking introduces harmful chemicals that directly injure blood vessel linings and can worsen cholesterol profiles. Diabetes, characterized by elevated blood sugar levels, also contributes to endothelial dysfunction. Obesity and a sedentary lifestyle are additional modifiable factors, as they often correlate with unfavorable cholesterol levels, higher blood pressure, and an increased risk of diabetes.
Non-modifiable risk factors cannot be changed. Advancing age increases the likelihood of developing atherosclerosis, as the condition progresses over many years and accelerates with age. Male gender is also associated with a higher risk, generally presenting earlier than in females. A family history of early-onset heart disease indicates a genetic predisposition, meaning an individual’s inherited traits can make them more susceptible to plaque buildup.
Associated Health Complications
The progression of atherosclerosis can lead to health complications when plaques severely narrow an artery or rupture. A ruptured plaque exposes its fatty contents to the bloodstream, triggering a blood clot, or thrombus. This clot can rapidly block the already narrowed artery, severely restricting or cutting off blood flow to tissues.
When atherosclerosis affects the arteries supplying the heart, it results in coronary artery disease (CAD). Reduced blood flow to the heart muscle can cause angina, which is chest pain or discomfort, especially during physical exertion. A complete blockage can lead to a myocardial infarction, commonly known as a heart attack, where a portion of the heart muscle dies due to lack of oxygen.
Plaque buildup in the carotid arteries, located in the neck and supplying blood to the brain, can cause carotid artery disease. This condition can lead to a transient ischemic attack (TIA), a “mini-stroke” with temporary neurological symptoms, or an ischemic stroke, which results in permanent brain damage due to prolonged blood flow interruption. Peripheral artery disease (PAD) occurs when arteries in the limbs, particularly the legs, become narrowed. This can cause pain, cramping, or numbness in the legs during activity, and in severe cases, lead to poor circulation and tissue death. Furthermore, narrowed renal arteries, which supply blood to the kidneys, can impair kidney function, potentially leading to chronic kidney disease.
Diagnosis and Management Strategies
Identifying atherosclerosis involves diagnostic tools to assess arterial damage and plaque buildup. Blood tests, such as a lipid panel, measure cholesterol and triglyceride levels, providing insight into risk factors. Blood pressure measurements detect hypertension, a contributor to arterial stress.
Imaging tests offer a direct view of the arteries. A coronary calcium scan detects calcium deposits in heart arteries, indicating early atherosclerosis. Carotid ultrasound visualizes plaque in neck arteries, while CT angiography provides detailed images of blood vessels. These tests help understand plaque location and severity.
Management of atherosclerosis involves a multi-pronged approach, starting with lifestyle modifications. Adopting a heart-healthy diet, such as the Mediterranean or DASH (Dietary Approaches to Stop Hypertension) eating plans, focuses on fruits, vegetables, whole grains, and lean proteins while limiting saturated fats, sodium, and added sugars. Regular physical activity, aiming for at least 150 minutes of moderate-intensity exercise per week, helps improve cholesterol levels, blood pressure, and weight management. Smoking cessation is advised to prevent further damage to blood vessels.
Medications manage risk factors and treat established disease. Statins lower LDL cholesterol, while antihypertensive drugs control high blood pressure. Antiplatelet agents, like aspirin, reduce blood clot formation. For advanced cases, medical procedures may be necessary. Angioplasty with stenting involves inflating a balloon to open a narrowed artery and placing a small mesh tube. Bypass surgery creates a new pathway for blood flow around a blocked artery, often using a healthy blood vessel from another part of the body.