We often hear about heart disease, heart attack, and stroke. But not much about atherosclerosis. However, this is the leading risk factor for a variety of cardiovascular problems.
Atherosclerosis is a long-term problem, also known as a chronic health problem. It builds up over time without any notice but is associated with severe complications.
After reading this article, you will understand atherosclerosis and its consequences.
What is atherosclerosis?
Atherosclerosis is a chronic health problem in which there’s a fibrous plaque building up in your blood vessels. This is called an atherosclerotic lesion.
It is a plaque made up of fatty acids, calcium, cholesterol, and several cells and substances you can find in the blood. This plaque buildup becomes hard and keeps growing in the artery lining. In time, it also limits the blood flow by preventing or narrowing the space.
As a result, you won’t have as much oxygen-rich blood to your organs. Smooth muscle cells, cardiac cells, neurons, and other cells need a constant supply. That’s why you can experience serious problems like stroke and heart attack as a consequence.
If you examine atherosclerosis in the microscope, you will see different parts or layers. Below the plaque, there is something called the endothelium. This is the artery lining and has many functions. It keeps blood flowing and contributes to immunity. Damage to the normal function of the endothelium may contribute to atherosclerosis.
In some cases, the hard covering of the atherosclerotic plaque breaks open. This is more common in larger arteries where the blood flows with a higher pressure. Platelets gather trying to close the gap, stick together, and cause blood clots. These contribute to some of the cardiovascular consequences of atherosclerosis (1,2,3).
The symptoms of atherosclerosis are not always obvious. It is initially an asymptomatic disease.
As the plaque builds up, patients may not feel anything at all. They start having symptoms when atherosclerosis becomes a real problem. When that happens, the plaque is already created.
In this late stage, symptoms of atherosclerosis include the following (3,4):
- Chest pain: This is one of the most feared symptoms of atherosclerosis. It only starts to appear when an atherosclerotic plaque obstructs the blood flow to your heart. Your heart muscle doesn’t get enough oxygen, and the cells start sending pain signals.
- Severe headache and neurological symptoms: This is also a feared symptom of atherosclerosis. It happens when atherosclerosis turns into a stroke. Headache is one of the symptoms, but you can also experience others—for example, slurred speech, weakness in your legs or arms, and numbness. Sometimes you can experience visual changes, too.
- Leg cramps: When the atherosclerotic plaque is found in your legs and arms, it usually triggers cramps and pain. This is called intermittent claudication. In simple terms, your leg or arm muscles do not get enough oxygen. When you increase the muscle activity, as in walking, you start experiencing leg cramps.
- High blood pressure: In some cases, atherosclerosis affects the kidneys. These organs are very susceptible to blood flow changes. In some cases, you may even experience kidney failure due to atherosclerosis. The kidney function is fundamental to control blood pressure. Thus, people with atherosclerosis are at a high risk of high blood pressure.
As you can see, there are no symptoms of atherosclerosis per se. Instead, you start getting symptoms when things are turning against you. Depending on the type of complication you’re experiencing, you can get either one symptom or the other. In any case, this is a late-stage, and you don’t want to get there.
But what if you want to know whether you should worry about atherosclerosis? You can take a look at risk factors, and they will guide you in this regard.
Risk factors are certain conditions that increase your risk for a given disease. In this case, risk factors for atherosclerosis include the following (3,4):
- Family history: Atherosclerosis has some genetic predisposition to it. Look out if you have a family with heart attack, stroke, and other complications of atherosclerosis. If that’s the case, atherosclerosis may be running in your family. Some of these conditions can be inherited because they have common atherosclerosis.
- Sedentary behavior: Living a sedentary lifestyle increases your risk of atherosclerosis. Doing regular exercise, on the other hand, maintains your heart muscle at its best. It also encourages blood flow in your arteries and improves your lipid profile.
- High blood pressure: Sustained high blood pressure makes your arteries weaker over time. It causes damage to the artery lining and predisposes to atherosclerosis. High blood pressure will also rupture atherosclerotic plaques. So, it is a risk factor for the development of atherosclerosis and its complications.
- Tobacco smoking: This is one of the most important risk factors you can change right now. Tobacco smoking is associated with thousands of substances that may damage your arteries. It is associated with inflammation, which is a fundamental step to create an atherosclerotic plaque.
- Diabetes: There’s a higher incidence of atherosclerosis among people with diabetes. These patients usually have blood lipid problems, inflammation, and many other risk factors at the same time. A longer time with the diagnosis and poorly controlled diabetes increase the risk.
- High cholesterol levels: LDL cholesterol levels are essential for the formation of atherosclerosis. We will cover this particular topic in the next section of this article. So, if you have high LDL cholesterol, there will be a higher chance of atherosclerosis.
- Obesity: Overweight and obesity are associated with insulin resistance, high blood pressure, high cholesterol levels, and other health problems. Thus, it is a type of patient with a potential case of atherosclerosis. Remember that obesity is a chronic condition, just like atherosclerosis. Thus, it encourages the building up of arterial plaques over a long period of time.
If you have one or several risk factors for atherosclerosis, we recommend talking to your doctor about it. It is also important to consider the treatment section in this article. In this section, you will find medical treatment and lifestyle changes you can apply right now.
What is the main cause of atherosclerosis?
Plaque buildup is a prolonged process. It sometimes begins during childhood. According to studies, even young people have some degree of atherosclerosis.
The exact cause is challenging to trace because there are many risk factors. But we know the basic process and the steps that cause atherosclerosis.
According to our current understanding of atherosclerosis, these are the main causes(1,2,3):
- High blood pressure: As mentioned above, high blood pressure affects the artery wall. It makes your body susceptible to vascular disease. Of course, you can also have atherosclerosis without high blood pressure.
- High cholesterol levels: Cholesterol level is an important modifier, especially high LDL cholesterol. LDL is a cholesterol particle that delivers fat to our tissues. An excess of LDL cholesterol causes excess fat in the arteries and other tissues. Conversely, HDL cholesterol is a particle that gathers excess fat from arteries and other tissues. That’s why it is known as “good” cholesterol.
- High triglyceride levels: LDL cholesterol is one of the main components of atherosclerosis. But the atherosclerotic plaque is also built with triglycerides.
- Chronic inflammation: Inflammation is a normal process in the blood. It is a part of the immune system. But chronic inflammation is not healthy and causes several problems. In the arteries, chronic inflammation promotes the oxidation of LDL particles. It also contributes to the formation of foam cells, as you will see next.
- Tobacco smoke: As mentioned above, tobacco contains a lot of unhealthy substances. Most of them trigger inflammation and contribute significantly to the formation of atherosclerosis.
As you can see, the causes are very similar to the risk factors. But if you want to understand the process, you may also want to read a step-by-step (2,3):
- Step 1. Endothelial dysfunction: The endothelium is the internal lining of the artery wall. This lining can be altered by physical stress, chemicals, inflammation, and other factors. In normal cases, the endothelium releases nitric oxide, which prevents atherosclerosis. But endothelial dysfunction causes a reduction of nitric oxide formation. Thus, it is the first step for the formation of the atherosclerotic plaque.
- Step 2. Lipid Layer formation within the intima: The endothelium is altered and completely disrupted. So, the barrier that keeps fatty acids in their place is no longer there. LDL cholesterol particles accumulate in this area. They make contact and bind with substances called proteoglycans. So, they become trapped in the intima layer of the artery wall.
- Step 3. Leucocyte migration: In normal circumstances, leukocytes defend the body against disease. In atherosclerosis, they adhere to the lipid layer that’s being formed. Along with fatty acids, leucocytes create a mass that keeps causing inflammation and recruiting more leukocytes.
- Step 4. Foam cell formation: Foam cells are simply macrophages that detect LDL and try to eat these particles to destroy them. But they become trapped in the atherosclerotic plaque. They accumulate and contribute to the progression of the plaque. Foam cells produce a lot of substances that trigger inflammation and make everything worse.
- Step 5. Progression of the plaque: As the plaque progresses, it is covered by a capsule. This capsule is known as a fibrous cap. It contains a combination of macrophages, foam cells, and smooth muscle cells. After this stage, the atheroma can become calcified or trigger hemorrhages.
On the formation and progression of the atherosclerotic plaque, we can also experience complications. Complications of atherosclerosis are the primary cause of concern. They arise when the arteries are partially or entirely blocked. So, you will have a different complication depending on the affected arteries (4):
- Coronary artery disease: This happens when atherosclerosis narrows the coronary arteries. These arteries are essential to delivering oxygen to your heart. In coronary atherosclerosis, the heart does not have sufficient blood flow. So, the heart muscle starts suffering from hypoxia. They release a series of substances that alert your body and cause severe chest pain. Patients usually start experiencing anginal pain (transient chest pain after exercise). But this is the first step for a heart attack if you don’t do anything about it. A plaque rupture may also lead to the acute coronary syndrome. In other words, you will have a sudden blood clot that prevents the artery and causes myocardial infarction.
- Carotid artery disease: This is when atherosclerosis causes a narrowing of the carotid artery. These arteries are essential to send blood to the brain. Thus, carotid artery disease predisposes to stroke. In some cases, patients have a transient ischemic attack (TIA) instead. The difference between one and the other is that stroke causes cell death, while TIA does not have lasting consequences.
- Peripheral artery disease: In some cases, peripheral artery disease develops before any of the above complications. This happens when the atherosclerotic plaque is found in your arms or legs. The arteries in your extremities are narrowed and affected by this plaque. You start having leg cramps and reduce your sensitivity to temperatures. It leads to poor circulation to the extremities and may even lead to severe cases, hypoxia, and gangrene.
- Aneurysm: An aneurysm is simply a bulge that forms in the affected artery. The artery wall becomes very thin as it starts losing certain layers. Thus, it becomes unable to maintain proper form against the blood flow. This happens even with normal blood pressure. One of the most common types of an aneurysm is the aortic aneurysm. Most of them do not have any symptoms, but they can be life-threatening if they burst and cause internal bleeding. If not, aneurysms may also produce blood clots that travel to smaller arteries, blocking their blood flow.
- Chronic kidney disease happens when the blocked artery is found in your kidneys or sends blood to the kidneys. The artery becomes narrow and does not send enough oxygenated blood to these organs. They require a lot of blood to function properly. So, after some time, your kidneys will start failing. You won’t filter the blood properly, and won’t be able to control your blood pressure.
All of these complications are usually detected very late in the development of atherosclerosis. When they are detected, they can be controlled. But in this stage, it is very difficult to reduce atherosclerotic plaque. Thus, it is essential to consider preventing these health problems if you don’t have them and opt for early treatment.
You might need treatment when you already have a narrowed artery or an atherosclerotic lesion starting. Treatment is more commonly applied in patients with a complication of atherosclerosis. The most common medical recommendations are as follows (5):
- Low-dose aspirin: This is a common medical recommendation after a cardiovascular event. It reduces the chance of a future stroke or heart attack.
- Statins: If you have high cholesterol levels, your doctor might recommend statins. This type of medication lowers your cholesterol levels and stabilize the atherosclerotic plaque.
- Surgical treatments: In some cases, patients may need a cardiac catheterization or a coronary artery bypass. This treatment is usually recommended in patients with angina or a previous heart attack.
- Lifestyle changes: These are perhaps the most important modifications. They work as a preventative measure and to complement your medical treatment. They include maintaining a healthy weight, eating healthily, and doing regular exercise. Everybody can adopt these lifestyle changes if they have risk factors to develop atherosclerosis.
Atherosclerosis is a silent health condition that develops over the years. It is associated with severe long-term consequences such as coronary heart disease.
Others include peripheral artery disease and chronic kidney disease. But even if you don’t develop any of these, atherosclerosis is increasing your risk of cardiovascular disease.
Thus, it is important to give attention to this problem if you have risk factors. For example, people with obesity, high cholesterol levels, diabetes, and high blood pressure should consider the possibility of atheroma formation in their arteries.
Luckily, we can do a lot to prevent the formation and the progression of atherosclerosis. We do it by combining medical treatments such as statins, aspirin, and certain surgical procedures with lifestyle changes.
In some cases, you may only need to exercise more often and eat healthily. But since every one of us is different, we encourage you to talk to your doctor if you feel worried about atherosclerosis.