What Is Atherosclerosis?
Atherosclerosis is when plaque -- a sticky substance made of cholesterol, fat, calcium, and other materials — builds up inside the walls of your arteries. Arteries are the blood vessels that carry blood from your heart throughout your body.
Atherosclerosis can put blood flow at risk as your arteries become blocked, and it can cause clots to form. It’s the usual cause of heart attacks, strokes, and peripheral artery disease (PAD) -- which together are called cardiovascular disease .
The condition doesn't just affect blood vessels in your heart. It can happen in any of your body's arteries. But it most often appears in the major arteries that supply blood to your heart, brain, stomach, lower body, and kidneys. You can both prevent and treat this process.
Arteriosclerosis. The names are similar, but atherosclerosis isn't exactly the same as arteriosclerosis. Arteriosclerosis is a stiffening and thickening of blood vessels that can restrict blood flow to the heart and other organs. It's sometimes called hardening of the arteries. Atherosclerosis is a type of arteriosclerosis.
Causes of Atherosclerosis
Doctors don't know exactly how atherosclerosis starts. But it's believed to begin when the endothelium, the thin layer of cells that lines your arteries, somehow gets damaged. It's a progressive disease that can begin in childhood.
Common causes of damage to the endothelium include:
- High cholesterol
- High blood pressure
- Inflammation, like from arthritis or lupus
- Obesity or diabetes
Stages of Atherosclerosis
When "bad" (LDL) cholesterol in your blood crosses a damaged endothelium, it enters the wall of your artery. Your white blood cells stream in to digest the LDL. Over the years, cholesterol and cells become plaque in the artery wall.
This plaque creates a bump on your artery wall. As atherosclerosis gets worse, the bump gets bigger. When it gets big enough, it can create a blockage.
Plaques from atherosclerosis can behave in different ways.
They can stay in your artery wall. There, the plaque grows to a certain size and then stops. Since this plaque doesn't block blood flow, it may never cause symptoms.
Plaque can grow in a slow, controlled way into the path of blood flow. Over time, it causes significant blockages. Pain in your chest or legs when you exert yourself is the usual symptom.
They can suddenly rupture. This allows blood to clot inside an artery. In your brain, this causes a stroke; in your heart, a heart attack.
The process of atherosclerosis begins with:
Fatty streak. A yellow strip lining the walls of major arteries, fatty streak has been found in children as young as 10. In the fatty streak stage, you feel no symptoms.
Fibrous plaque. The second and more dangerous phase of atherosclerosis begins when the cholesterol-containing plaque expands into blood vessels -- the bump.
Complicated lesion. In the last and most serious stage of atherosclerosis, the plaque begins to break up. This exposes the cholesterol and tissue beneath it, causing unseen but serious harm that your immune system tries to fight off. Blood-clotting cells, which block blood flow, are formed in response. The blood clots, combined with the exposed plaque, create what's called a complicated lesion.
Symptoms of Atherosclerosis
You might not have symptoms until your artery is nearly closed or until you have a heart attack or stroke. Symptoms can also depend on which artery is narrowed or blocked.
Symptoms related to your coronary arteries include:
- Arrhythmia, an unusual heartbeat
- Pain or pressure in your upper body, including your chest, arms, neck, or jaw. This is known as angina.
- Shortness of breath
Symptoms related to the arteries that deliver blood to your brain include:
- Numbness or weakness in your arms or legs
- A hard time speaking or understanding someone who’s talking
- Drooping facial muscles
- Severe headache
- Trouble seeing in one or both eyes.
Symptoms related to the arteries of your arms, legs, and pelvis include:
- Leg pain when walking, called intermittent claudication
- Cold feet
- Aching or burning in your toes and feet when you're at rest
- Frequent sores or infections on your feet that won't heal
Symptoms related to your kidneys include:
- High blood pressure
- Kidney failure
Risk Factors for Atherosclerosis
Atherosclerosis starts when you’re young. Research has found that even teenagers can have signs.
If you’re 40 and generally healthy, you have about a 50% chance of getting serious atherosclerosis in your lifetime. The risk goes up as you get older. Most adults over 60 have some atherosclerosis, but most don’t have noticeable symptoms.
The following can increase your risk of atherosclerosis. These risk factors are behind more than 90% of all heart attacks:
- Abdominal obesity ("spare tire")
- Diabetes and insulin resistance
- Family history of heart disease
- High alcohol intake (more than one to two drinks a day, depending on your size)
- High blood pressure
- High LDL cholesterol
- High levels of C-reactive protein (CRP) in your blood, which is a signal of inflammation
- High triglycerides
- Not eating fruits and vegetables
- Not exercising regularly
- Sleep apnea
Rates of death from atherosclerosis have fallen 25% in the past 3 decades. This is because of improved treatments and lifestyles.
Your doctor will start with a physical exam. They’ll listen to your arteries and check for weak or absent pulses.
You might need tests, including:
- Angiogram, in which your doctor puts dye into your arteries so they’ll be visible on an X-ray
- Ankle-brachial index, which compares blood pressures in your lower leg and arm
- Blood tests to look for things that raise your risk of atherosclerosis, like high cholesterol or blood sugar
- Carotid ultrasound, an imaging test that shows whether there's hardening of the arteries in your neck
- Abdominal ultrasound, which checks for bulges or excess plaque in the aorta, the main artery supplying blood to your lower body
- Chest X-ray
- CT scan or magnetic resonance angiography (MRA) to look for hardened or narrowed arteries. This is also known as a coronary calcium scan or heart scan.
- Doppler ultrasound, which measures blood flow in your arteries.
- Echocardiogram, which takes images of the chambers and valves in your heart to see how well it pumps
- EKG, or electrocardiogram, a record of your heart’s electrical activity
- Stress test, in which you exercise while health care professionals watch your heart rate, blood pressure, and breathing.
You might also need to see doctors who specialize in certain parts of your body, like cardiologists or vascular specialists, depending on your condition.
Complications of Atherosclerosis
Complications of atherosclerosis include:
- Chronic kidney disease
- Coronary or carotid heart disease
- Heart attack
- Heart failure
- Peripheral artery disease
- Unusual heart rhythms
The plaques of atherosclerosis cause the three main kinds of cardiovascular disease:
- Coronary artery disease: Stable plaques in your heart's arteries cause angina (chest pain). Sudden plaque rupture and clotting cause heart muscle to die. This is a heart attack.
- Cerebrovascular disease: Ruptured plaques in your brain's arteries cause strokes with the potential for permanent brain damage. Temporary blockages in your artery can also cause something called transient ischemic attacks (TIAs), which are warning signs of a stroke. They don’t cause any brain injury.
- Peripheral artery disease: When the arteries in your legs narrow, it can lead to poor circulation. This makes it painful for you to walk. Wounds also won’t heal as well. If you have a severe form of the disease, you might need to have a limb removed (amputation).
Once you have a blockage, it's generally there to stay. But with medication and lifestyle changes, you can slow or stop plaques. They may even shrink slightly with aggressive treatment.
Lifestyle changes: You can slow or stop atherosclerosis by taking care of the risk factors. That means a healthy diet, exercise, and no smoking. These changes won't remove blockages, but they’re proven to lower the risk of heart attacks and strokes.
Medication: Drugs for high cholesterol and high blood pressure will slow and may even halt atherosclerosis. They lower your risk of heart attack and stroke. Diabetes raises the risk for atherosclerosis, so taking medicines to control your diabetes can help lower your risk. Your doctor may prescribe antiplatelet medicines like aspirin, a blood thinner, to help prevent clots. Because long-term aspirin use can cause stomach bleeding, talk with your doctor before you start taking it every day.
Your doctor can use more invasive techniques to open blockages from atherosclerosis or go around them:
- Angiography and stenting: Your doctor puts a thin tube into an artery in your leg or arm to get to diseased arteries. Blockages are visible on a live X-ray screen. Angioplasty (using a catheter with a balloon tip) and stenting can often open a blocked artery. Stenting helps ease symptoms, but it does not prevent heart attacks.
- Bypass surgery: Your doctor takes a healthy blood vessel, often from your leg or chest, and uses it to go around a blocked segment.
- Endarterectomy: Your doctor goes into the arteries in your neck to remove plaque and restore blood flow. They also may place a stent in higher-risk patients.
- Fibrinolytic therapy: A drug dissolves a blood clot that’s blocking your artery.
You can make changes to your lifestyle to prevent atherosclerosis or slow down its progression. Some things that may help:
- Lower your stress through yoga, mindfulness, or deep breathing. These practices can help lower your blood pressure too.
- Stop smoking (and vaping), which raises your risk for heart disease. Nicotine narrows blood vessels, forcing your heart to work harder. Quitting smoking is one of the most important lifestyle changes you can make to prevent damage to your heart from atherosclerosis.
- Follow a healthy diet rich in low-fat proteins, fish, fruits, vegetables, and whole grains. This will help you manage your weight and lower cholesterol, blood pressure, and blood sugar levels.
- Lose weight and keep it off. Even a small amount will help lower your risk.
- Exercise regularly to maintain a healthy blood pressure and improve blood flow. Aim for at least 150 minutes of moderate exercise or 75 minutes of brisk exercise a week.
- Keep on top of your other health conditions by having regular checkups and following your doctor's treatment plan.
It takes years for atherosclerosis to develop into noticeable symptoms like leg and chest pain, high blood pressure, and kidney failure. Healthy habits like exercise, a low-fat and balanced diet, not smoking, and lowering stress will help prevent or slow damage to your heart and other organs due to atherosclerosis. Pay attention to your body and keep up with your regular visits to your doctor.
What are six symptoms of atherosclerosis?
Your symptoms will vary depending on which artery is affected. They may include:
- Heart palpitations
- Angina (chest pain)
- Shortness of breath
- Problems with thinking or memory
- Leg pain while walking
- Erection problems
What are the four stages of atherosclerosis?
- Damage to the endothelium. When the layer of cells that lines your artery walls is damaged, this starts a process that leads to inflammation there.
- Fatty streak. This yellow streak results when your white blood cells mount an immune response.
- Fibrous plaque. As cells keep building up, the fatty streak gets bigger. Muscle cells grow over the top of it, forming what's called a fibrous plaque. This narrows your artery, making it harder for blood to flow.
- Complicated lesion. This forms when the fibrous plaque ruptures, exposing the tissue and cholesterol beneath. This leads to the formation of a blood clot, which further hinders blood flow. It can also lead to a stroke or heart attack.
What is the life expectancy of someone with atherosclerosis?
A healthy diet and lifestyle and regular checkups can help slow the progress of atherosclerosis. Without these changes, your life expectancy is significantly shortened -- 16 years on average with a heart attack, 10 with heart failure, and maybe even more after a stroke. Adopting a healthy lifestyle could add more than a decade to your life.