What Is Atherosclerosis?
Atherosclerosis is a hardening and narrowing of your arteries caused by cholesterol plaques lining the artery over time. It can put blood flow at risk as your arteries become blocked.
You might hear it called arteriosclerosis or atherosclerotic cardiovascular disease. It’s the usual cause of heart attacks, strokes, and peripheral vascular disease -- what together are called cardiovascular disease.
You can prevent and treat this process.
What Causes Atherosclerosis?
Arteries are blood vessels that carry blood from your heart throughout your body. They're lined by a thin layer of cells called the endothelium. It keeps the inside of your arteries in shape and smooth, which keeps blood flowing.
Atherosclerosis begins with damage to the endothelium. Common causes include:
- High cholesterol
- High blood pressure
- Inflammation, like from arthritis or lupus
- Obesity or diabetes
- Smoking
That damage causes plaque to build up along the walls of your arteries.
When bad cholesterol, or LDL, 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 wall of your artery.
Plaque creates a bump on your artery wall. As atherosclerosis gets worse, that bump gets bigger. When it gets big enough, it can create a blockage.
That process goes on throughout your entire body. It’s not only your heart at risk. You’re also at risk for stroke and other health problems.
Atherosclerosis usually doesn’t cause symptoms until you’re middle-age or older. As the narrowing becomes severe, it can choke off blood flow and cause pain. Blockages can also rupture suddenly. That causes blood to clot inside an artery at the site of the rupture.
What Are the 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
- Paralysis
- 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
- Numbness
What Are the 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 older than 60 have some atherosclerosis, but most don’t have noticeable symptoms.
These risk factors are behind more than 90% of all heart attacks:
- Abdominal obesity ("spare tire")
- Diabetes
- High alcohol intake (more than one drink for women, one or two drinks for men, per day)
- High blood pressure
- High cholesterol
- Not eating fruits and vegetables
- Not exercising regularly
- Smoking
- Stress
Rates of death from atherosclerosis have fallen 25% in the past 3 decades. This is because of better lifestyles and improved treatments.
How Do You Diagnose Atherosclerosis?
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, a test to compare blood pressures in your lower leg and arm
- Blood tests to look for things that raise your risk of having atherosclerosis, like high cholesterol or blood sugar
- CT scan or magnetic resonance angiography (MRA) to look for hardened or narrowed arteries
- EKG, 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.
How Does Plaque Affect Atherosclerosis?
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.
The worst happens when plaques suddenly rupture, allowing blood to clot inside an artery. In your brain, this causes a stroke; in your heart, a heart attack.
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).
What Are the Complications of Atherosclerosis?
Complications of atherosclerosis include:
- Aneurysms
- Angina
- Chronic kidney disease
- Coronary or carotid heart disease
- Heart attack
- Heart failure
- Peripheral artery disease
- Stroke
- Unusual heart rhythms
How Do You Treat Atherosclerosis?
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.
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 higher risk patients.
- Fibrinolytic therapy: A drug dissolves a blood clot that’s blocking your artery.
Your doctor will discuss the complications of these procedures with you.