The disease disrupts the flow of blood around the body, posing serious cardiovascular complications. In this article, we will explain how and why atherosclerosis develops; we will also discuss its symptoms, treatment, and diagnosis.
Contents of this article:
What is atherosclerosis?
The arteries carry blood from the heart; damage to the cell lining (endothelium) causes atherosclerosis.
Arteries carry blood from the heart to the rest of the body. They are lined by a thin layer of cells that keeps them smooth and allows blood to flow easily; this is called the endothelium.
Atherosclerosis starts when the endothelium becomes damaged, allowing low-density lipoproteins (LDL - bad) cholesterol to accumulate in the artery wall.
The body sends macrophages - a type of white blood cell - to clean up this cholesterol, but, sometimes, the cells get stuck at the affected site. Over time, a plaque can build up, made of cholesterol, macrophages, calcium, and other substances from the blood.
Sometimes, the plaque grows to a certain size and stops growing, causing the individual no problems. However, sometimes, the plaque clogs up the artery, disrupting the flow of blood around the body. This makes blood clots more likely, which can result in life-threatening conditions.
In some cases, the plaque eventually, breaks open. If this happens, blood cell fragments, called thrombocytes (or platelets), accumulate in the affected area. These fragments may then stick together, forming blood clots. In the brain this can cause strokes, in the heart it can cause a heart attack.
The condition can affect the entire artery tree, but mainly affects the larger high-pressure arteries.
Causes of atherosclerosis
Certain factors can damage the inner area of the artery (endothelium) and can trigger atherosclerosis; these factors include:
- hypertension (high blood pressure)
- high levels of cholesterol
- high levels of sugar in the blood
Certain people have a higher risk of developing the condition:
- Diabetes - patients with poorly controlled diabetes, who frequently have high blood glucose levels, are 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 - exposure to air pollution appears to increase the risk of cholesterol build-up in the coronary arteries.
Symptoms of atherosclerosis
The first signs of atherosclerosis can begin to develop during adolescence, with streaks of white blood cells appearing on the artery wall. Most often, there are no symptoms until a plaque ruptures or the blood flow is very restricted, which typically takes many years to occur.
The symptoms depend on which arteries are affected:
Carotid arteries provide blood to the brain; when the blood supply is limited, patients can suffer stroke and may experience:
- difficulty breathing
- facial numbness
Chest pain can be a symptom of atherosclerosis affecting the coronary articles.
Coronary arteries provide blood to the heart; when the blood supply to the heart is limited, it can cause angina and heart attack; symptoms include:
- extreme anxiety
- chest pain
- feeling faint
Renal arteries 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
In peripheral arterial disease, the arteries to the limbs (most commonly 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 can 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
Arteriosclerosis vs. atherosclerosis
Arteriosclerosis and atherosclerosis are different conditions:
- Arteriosclerosis is the stiffening or hardening of the artery walls.
- Atherosclerosis is the narrowing of the artery because of plaque build-up. Atherosclerosis is a specific type of arteriosclerosis.
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.
Those who are at risk of developing atherosclerosis should be tested because 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 the blood. If there are high levels of fat and sugar, it could indicate an increased risk of atherosclerosis.
- The doctor will listen to the arteries using a stethoscope to see if there is an unusual "whooshing" due to uneven blood flow - called a bruit. If a bruit is heard, 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 can check 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 can be used to find arteries that are hardened and narrowed.
Treatments 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. A doctor may recommend eating foods high in soluble fiber and limiting intake of saturated fats, sodium (salt), and alcohol.
Medication - some medications can prevent the build up of plaque or help prevent blood clots (antiplatelets). Other medications, such as statins, might 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.
Prevention of atherosclerosis
Living a health lifestyle is the best way to limit the risk of developing atherosclerosis.
Diet - Try to avoid saturated fats, they increase levels of bad cholesterol. The following foods are high in unsaturated fats and can help keep bad cholesterol levels down:
- olive oil
- oily fish
Exercise - exercise will improve fitness levels and lower blood pressure; it will also help weight loss.
Smoking - this is one of the major risk factors for atherosclerosis, it also raises blood pressure. Smokers should quit as soon as possible and arrange a meeting with their doctor about ways to give up and manage withdrawal symptoms.