Atherosclerosis (Hardening of the Arteries)

How atherosclerosis develops

1. Damage to the artery lining: high blood pressure, smoking, high blood sugar and inflammation injure the endothelium, the thin inner lining.
2. Cholesterol entry: LDL ("bad") cholesterol particles slip into the artery wall and become oxidized.
3. Inflammation: white blood cells move in to clear the cholesterol, turning into "foam cells" and forming a fatty streak. This can begin in childhood.
4. Plaque growth: over years, smooth muscle cells, calcium and scar tissue build a plaque with a fibrous cap.
5. Narrowing or rupture: a large plaque reduces blood flow, causing symptoms on exertion. More dangerously, a plaque can crack, and a blood clot forms on it within minutes, suddenly blocking the artery. This causes most heart attacks and many strokes, often in plaques that were not severely narrowing.

Arteriosclerosis is the broader term for stiffening of arteries from any cause; atherosclerosis is its most common and important form.

Where atherosclerosis causes problems

Risk factors

Modifiable

• High LDL cholesterol and other atherogenic lipids, including high lipoprotein(a)
• High blood pressure
• Smoking and secondhand smoke
• Diabetes and prediabetes
• Obesity, especially around the waist
• Physical inactivity
• Unhealthy diet: high in saturated and trans fats, salt, processed meat and refined carbohydrates
• Chronic kidney disease, chronic inflammatory diseases (rheumatoid arthritis, lupus, psoriasis) and HIV
• Heavy alcohol use and poor sleep

Not modifiable

• Age: risk rises from around 45 in men and 55 in women
• Male sex, although heart disease is the leading cause of death in women too
• Family history of early heart disease (before 55 in a male relative or 65 in a female relative)
• Genetic conditions such as familial hypercholesterolemia

Symptoms

Atherosclerosis causes no symptoms until an artery is narrowed by roughly 70 percent or more, or a plaque ruptures. Then symptoms depend on the artery involved:

• Heart: angina, a squeezing chest discomfort on exertion that eases with rest; breathlessness; fatigue. Women, older adults and people with diabetes may have subtler symptoms.
• Brain: sudden one-sided weakness, numbness, speech or vision problems.
• Legs: cramping pain in the calf, thigh or buttock while walking, eased by rest.
• Kidneys: high blood pressure that is hard to control.

The first sign can be a heart attack or stroke, which is why risk assessment matters.

Diagnosis

• Risk assessment: doctors use tools such as the AHA PREVENT calculator to estimate your 10-year risk from age, cholesterol, blood pressure, diabetes, smoking and kidney function.
• Blood tests: lipid panel (LDL, HDL, triglycerides), lipoprotein(a), blood sugar or HbA1c, kidney function.
• Coronary artery calcium (CAC) score: a quick CT scan that measures calcified plaque; it helps decide on treatment when risk is uncertain.
• Ankle-brachial index: compares blood pressure at the ankle and arm to detect leg artery disease.
• Ultrasound: of the carotid arteries, leg arteries or abdominal aorta.
• Stress testing: exercise ECG, stress echocardiogram or nuclear scan to detect reduced blood flow to the heart.
• CT coronary angiography or invasive angiography to see narrowed arteries directly.

Treatment

Lifestyle changes

• Stop smoking: the single most powerful step; risk falls within months.
• Eat a heart-healthy diet: vegetables, fruits, whole grains, legumes, nuts, fish and olive oil, as in Mediterranean-style or DASH diets; limit saturated fat, salt, processed meat and sugary drinks.
• Exercise: at least 150 minutes of moderate activity a week.
• Reach and keep a healthy weight.
• Limit alcohol and get enough sleep.

Medicines

• Statins lower LDL cholesterol, stabilize plaque and reduce heart attacks and strokes; they are the foundation of treatment.
• Ezetimibe, PCSK9 inhibitors, bempedoic acid and inclisiran for further LDL lowering when needed.
• Antiplatelet medicines (low-dose aspirin or clopidogrel) for people with established disease; aspirin is no longer routinely recommended for prevention in people without disease because of bleeding risk.
• Blood pressure medicines to reach targets.
• Diabetes medicines, including GLP-1 receptor agonists and SGLT2 inhibitors, which also reduce cardiovascular events in people with diabetes.
• Angina medicines such as nitrates and beta-blockers for symptoms.

Procedures

• Angioplasty and stenting: a balloon opens the narrowed artery and a mesh tube keeps it open.
• Bypass surgery: a blood vessel graft routes blood around the blockage (coronary or leg bypass).
• Carotid endarterectomy or stenting: removes or treats plaque in the neck arteries in selected patients.

Complications

Heart attack, stroke, heart failure, irregular heart rhythms, sudden cardiac death, limb loss from critical limb ischemia, kidney failure and aortic aneurysm rupture.

Prevention

Atherosclerosis begins early in life, so prevention is lifelong: avoid smoking, stay active, eat well, keep a healthy weight and have blood pressure, cholesterol and blood sugar checked. Adults should have cholesterol checked at least every 4 to 6 years, more often with risk factors. People with familial hypercholesterolemia need treatment from a young age.

Frequently asked questions

What is atherosclerosis in simple terms?

It is the gradual buildup of fatty plaque inside the walls of your arteries, which narrows and stiffens them. Over years it can reduce blood flow or trigger a clot, causing angina, heart attack, stroke or leg pain.

Can atherosclerosis be reversed?

Not fully, but it can be slowed and partly reversed. Intensive LDL lowering with statins and other medicines, stopping smoking and lifestyle changes can shrink plaque slightly and, more importantly, stabilize it so it is less likely to rupture. This greatly cuts the risk of heart attack and stroke.

What are the early signs of atherosclerosis?

Usually there are none. When symptoms appear, they include chest discomfort or breathlessness on exertion, leg pain when walking, erectile dysfunction, or brief stroke-like episodes. Because it is often silent, checking blood pressure, cholesterol and blood sugar is essential.

What is the difference between arteriosclerosis and atherosclerosis?

Arteriosclerosis is a general term for thickening and stiffening of the arteries from any cause, including aging and high blood pressure. Atherosclerosis is a specific type caused by fatty plaque buildup in the artery wall. It is the most common and clinically important form.

Who should take a statin?

Statins are recommended for people with established cardiovascular disease, very high LDL cholesterol (190 mg/dL or more), diabetes in adults aged 40 to 75, and people whose estimated 10-year risk is raised. Your doctor will weigh your risk score, calcium score and preferences.