What Is Atherosclerosis?

Atherosclerosis (or arteriosclerotic vascular disease) is a condition where the arteries become narrowed and hardened due to an excessive build up of plaque around the artery wall. The disease disrupts the flow of blood around the body, posing serious cardiovascular complications.


Arteries contain what is called an endothelium, a thin layer of cells that keeps the artery smooth and allows blood to flow easily. Atherosclerosis starts when the endothelium becomes damaged, allowing LDL cholesterol to accumulate in the artery wall. The body sends macrophage white blood cells to clean up the cholesterol, but sometimes the cells get stuck there at the affected site. Over time this results in plaque being built up, consisting of bad cholesterol (LDL cholesterol) and macrophage white blood cells.

The plaque clogs up the artery, disrupting the flow of blood around the body. This potentially causes blood clots that can result in life-threatening conditions such as heart attack,stroke and other cardiovascular diseases. 

The condition can affect the entire artery tree, but mainly affects the larger high-pressure arteries. 

What is the Difference Between Arteriosclerosis and Atherosclerosis?

Arteriosclerosis is the stiffening or hardening of the artery walls.

Atherosclerosis is the narrowing of the artery because of plaque build-up.

All patients with atherosclerosis have arteriosclerosis, but those with arteriosclerosis might not necessarily have atherosclerosis. However, the two terms are frequently used with the same meaning.

What are the Signs and Symptoms of Atherosclerosis?

A symptom is something the patient feels and describes, such as pain, while a sign can be detected by other people, such as a rash.

The first signs of atherosclerosis can begin to develop during adolescence, with streaks of white blood cells appearing on the artery wall. The symptoms of the disease depend on which arteries are affected: 

Carotid Arteries - these arteries provide blood to the brain, when the blood supply is limited patients can suffer stroke and may experience:

• Weakness
• Difficulty breathing
• Headache
• Facial numbness
• Paralysis

Coronary Arteries - these arteries provide blood to the heart, when the blood supply to the heart is limited it can cause angina and heart attack, symptoms include:

• Vomiting
• Extreme anxiety
• Chest pain
• Coughing
• Feeling faint

Renal Arteries- these supply blood to the kidneys; if the blood supply becomes limited, there is a serious risk of developing chronic kidney disease, and the patient may experience:

• Loss of appetite
• Swelling of the hands and feet
• Difficulty concentrating

Peripheral arterial disease - the arteries to the limbs, usually the legs, are blocked. The most common symptom is leg pain, either in one or both legs, usually in the calves, thighs or hips. The pain may be described as one of heaviness, cramp, or dullness in the leg muscles. Other symptoms may include:

• Hair loss on legs or feet
• Male impotence (erectile dysfunction)
• Numbness in the legs
• The color of the skin on the legs change
• The toenails get thicker
• Weakness in the legs

What are the Causes of Atherosclerosis?

The condition is caused by macrophage white blood cells and fat that accumulate in arteries - the white blood cells are originally sent by the body's immune system to clean up LDL cholesterol pockets. When they stick to an artery they secrete a molecule called netrin-1, this stops normal migration of the macrophages out of the arteries. As a result, what you have left is a mixture of clumped up cholesterol pockets and white blood cells, this is the plaque that can disrupt blood flow.

A study carried out by researchers at NYU Langone Medical Center is said to have been the first of its kind to explain why macrophages stick to artery walls. 

Certain factors that can damage the inner area of the artery (endothelium) and can trigger atherosclerosis include:

• High Blood Pressure
• High levels of cholesterol
• Smoking
• High levels of sugar in the blood

Areas of the artery that are damaged are likely to have plaque build up which can eventually break open. When the plaque breaks open, blood cell fragments called thrombocytes (or platelets) accumulate at the affected area. These fragments can then stick together, forming blood clots.

Diabetes - patients with poorly-controlled diabetes, who frequently have excess blood glucose levels, are much more likely to develop atherosclerosis.

Genetics - people with a parent or sibling who has/had atherosclerosis and cardiovascular disease have a much higher risk of developing atherosclerosis than others.

Air pollution - in 2007, researchers from the University of California in Los Angeles linked exposure to diesel exhaust particles in air pollution to a higher risk of bad cholesterol build-up in the arteries.

Diagnosing Atherosclerosis

Those who are at risk of developing atherosclerosis should be tested, as the symptoms don't show until cardiovascular disease develops. A diagnosis will be based on the medical history of a patient, test results and a physical exam. 

Blood tests - these measure how much sugar, fat and protein there is in your blood. If there are high levels of fat and sugar it can be an indicator that you're at risk of developing the condition. 

Physical exam

• The doctor will listen to the arteries using a stethoscope to see if there is an unusual "whooshing" sound reflecting turbulence of flow - called a bruit. If a bruit is heard then it can mean there is plaque obstructing blood flow.
• There may also be a very weak pulse below the area of the artery that has narrowed. Sometimes there is no detectable pulse.
• An affected limb may have abnormally low blood pressure
• There may be signs of an aneurysm (pulsating bulge) behind the patient's knee or in their abdomen
• Where blood flow is restricted, wounds may not heal properly

Ultrasound - an ultrasound scanner is able to create a picture of the inside of your body using sound waves. It can check your blood pressure at distinct parts of the body; changes in pressure indicate where arteries may have obstruction of blood flow. 

Computed tomography (CT) scan - A CT scan uses X-ray images to create detailed pictures of the inside parts of the body. It can be used to find arteries that are hardened and narrowed.

What are the Treatment Options for Atherosclerosis?

Those who are at risk of developing atherosclerosis will likely be told by their doctor to change their lifestyle and maintain a healthy weight. In some cases treatment may include medication or surgery. 

Lifestyle Changes- The changes will focus on weight management, physical activity and a healthy diet. Your doctor may recommend eating foods high in soluble fiber and limiting your intake of saturated fats, sodium and alcohol. For more information on what a healthy diet is (Click here).

Medication - The doctor may prescribe medications to prevent the build up of plaque or to help prevent blood clots (anteplatelets). Other medications such as statins may be prescribed to lower cholesterol, and Angiotensin-converting enzyme (ACE) inhibitors to lower blood pressure. 

Surgery - Severe cases of atherosclerosis may be treated by surgical procedures, such as angioplasty or coronary artery bypass grafting (CABG).

Angioplasty involves expanding the artery and opening the blockage, so that the blood can flow through properly again. CABG is another form of surgery that can improve blood flow to the heart by using arteries from other parts of the body to bypass a narrowed coronary artery.

Altering Calcium Build-Up In Blood Vessels - New Treatment for Atherosclerosis?

Scientists from Seoul National University, South Korea, reported in PLoS Biology that they identified the cells responsible for creating calcium build-up in vessel walls, which eventually lead to atherosclerosis and heart disease.

Dr. Hyo-Soo Kim and team explained that the system of calcium accumulation in blood vessels is not that different to what occurs during bone formation - it consists of maintaining a balance between osteoblasts (bone-producing cells) and osteoclasts (bone-eliminating cells).

In their study the team categorized the starting point of a population of vascular-calcifying progenitor cells, and how likely they were to differentiate into different kinds of cells.

Dr Kim explained "We show that vascular calcifying progenitor cells in the artery have the potential to become either osteoblasts or osteoclasts. And a certain chemical can push these cells towards becoming osteoclasts, which leads to the softening of the blood vessels."

The researchers organized the cells from mice aortas into two groups, both of which came from bone marrow and expressed Sca-1, a cell-surface protein. However, only one group expressed another surface protein - PDGFRa. Cells that expressed just Sca-1 could develop into osteoblasts or osteoclasts, while those that expressed both Sca-1 and PDGFRa only became osteoblasts.

When the cells were treated with PPARy, a protein that aids in the production of osteoclasts and blocks osteoblast production, only Sca-1 expressed cells differentiated into osteoclast-like cells.

They also found that while cells that could turn into either osteoblasts or osteoclasts were administered into mouse models of atherosclerosis raised the severity of calcium accumulation in arteries, cells treated with PPARy considerably reduced this effect and reversed calcification.

The team concluded "These findings suggest that a subtype of calcifying progenitor cells offer a new therapeutic target for the prevention of calcification. This opens up the possibility of new drug development to inhibit the hardening of the arteries, and thereby reduce the risk of heart disease."

Prevention of Atherosclerosis

The best way to prevent atherosclerosis is to eliminate any risk factors you might have. The best way to do this is by living a healthy lifestyle. 

Diet- Try to avoid saturated fats, they increase your levels of bad cholesterol. The following foods are high in unsaturated fats and can help keep bad cholesterol levels down:

• olive oil
• avocados
• walnuts
• oily fish
• nuts
• seeds

Exercise- exercise will improve your fitness level and lower your blood pressure. If you are overweight then exercise can help you lose weight through activities such as walking, swimming, and cycling. To find out if you are overweight, click here.

Smoking- this is one of the major risk factors for atherosclerosis, it also raises your blood pressure. If you are a smoker you should quit as soon as possible and arrange a meeting with your doctor about ways you can give up and manage the withdrawal symptoms.

Flu vaccine - researchers from the School of Public Health and Community Medicine in Australia say that the flu vaccination may reduce the risk of heart attack by 50% in middle-aged individuals with narrowed arteries.