Atherosclerosis, also known as arteriosclerosis and hardening of the arteries, is the condition when arteries become stiff and fatty deposits begin to accumulate on the walls of the arteries, which result in restricted blood flow to the organs and tissues.

The precise cause of atherosclerosis is still unknown. However, various studies indicate that atherosclerosis may start in childhood and progress slowly, but tends to develop faster with age.

The risk factors that can lead to atherosclerosis include high levels of cholesterol, high blood pressure, smoking, and diabetes. A complex series of events is involved in the pathogenesis of atherosclerosis, events that eventually lead to the formation of atherosclerotic plaque.

Generally, atherosclerosis presents no symptoms until the affected arteries are either critically narrowed or entirely blocked. However, some people may have signs and symptoms that mainly depend on which arteries are affected. In case of coronary arteries, chest pain (angina) will appear. If carotid arteries are affected, symptoms of a stroke that may include confusion, paralysis or numbness, and loss of consciousness may appear. Atherosclerosis in peripheral arteries may lead to a disease called peripheral artery disease. Chronic kidney disease may develop and cause a slow loss of kidney function if renal arteries are affected by atherosclerosis.

In order to come at a correct diagnosis for atherosclerosis, a doctor may perform a physical exam or order certain diagnostic tests that may include blood tests, electrocardiogram (ECG), chest X-ray, echocardiography, computed tomography scan.

Treatment options for atherosclerosis usually involve heart-healthy lifestyle changes and medications, but severe cases may require a surgical intervention.

Atherosclerosis can cause serious complications, sometimes called atherosclerotic diseases, such as coronary heart disease, carotid artery disease, peripheral artery disease, and aneurysms.

Adopting a healthy lifestyle is the only way to prevent such diseases. A healthy lifestyle may include consuming heart-healthy foods, physical activity, quitting smoking, and weight control.

From an epidemiological perspective, a significant drop has been observed in the mortality and incidence of atherosclerotic diseases, mainly ischemic heart disease and ischemic stroke, since the middle of the 20th century in high-income countries.

 According to an article published in the American journal Circulation Research, in the last few decades, the majority of low- and middle-income countries saw a decline in mortality from ischemic stroke, but mortality from ischemic heart disease remains varied with countries showing declines, while others showing increases.

Atherosclerosis is a condition that causes arteries to lose their flexibility and elasticity, becoming stiff. Atherosclerosis refers to the buildup of fatty substances called plaques that narrow and clog the arteries. This stiffness and narrowing due to the buildup of plaques may result in restricting adequate amounts of oxygenated blood from reaching organs and tissues.

Atherosclerosis can manifest in a wide range of vascular diseases depending on the arteries affected. These diseases, sometimes called atherosclerotic diseases, include ischemic heart disease, ischemic stroke, peripheral arterial disease, and chronic kidney disease.

Atherosclerosis may start in childhood, but the precise cause is still unknown. Multiple risk factors play a role in the development of atherosclerosis. Scientists believe that it starts with damage to the inner layer of arteries, called endothelium.

Certain factors increase the chance of damage to the inner layers of arteries; these factors include:

• High levels of cholesterol: This refers to increased levels of low-density lipoprotein and decreased levels of high-density lipoprotein, known as bad and good cholesterol, respectively.
• High blood pressure: Hypertension can dramatically increase the possibility of having atherosclerosis.
• Smoking: Smoking can cause damage to blood vessels and tighten them. In addition, smoking can raise cholesterol levels and blood pressure.
• Insulin resistance: This condition is marked by the body’s inability to appropriately use its insulin, leading to high blood sugar levels.
• Diabetes: It is one of the major risk factors that can lead to atherosclerosis.
• Being overweight: People who are overweight are more susceptible to atherosclerosis.
• Lack of physical activity: Burning calories can decrease the possibility of having atherosclerosis by eliminating other risk factors, such as obesity.
• Imbalanced diet: Eating unhealthy amounts of foods high in saturated fats, salt, and sugar can make the person susceptible to atherosclerosis.
• Age: In men, the risk of having atherosclerosis increases after age 45. In women, the risk increases after age 55.
• Family history: The risk of having atherosclerosis increases if a blood relative was diagnosed with early heart disease.

Atherosclerosis is a systemic disease that can influence the entire arterial tree. Atherosclerosis is a complex series of events that lead to the formation of atherosclerotic plaque.

Dysfunction of endothelial cell, cells that form the lining of the interior surface of blood vessels, caused by damage to the artery’s walls sets off the process. This dysfunction allows lipoproteins, such as bad cholesterol, to the enter the artery’s intima, its innermost layer. White blood cells are attracted to the activated endothelial cells, leading to their accumulation in the wall of the artery.

This process leads to the production of an excessive amount of connective tissue matrix, which is the collection of extracellular molecules, such as collagen, found between connective tissue cells to provide structural and biochemical support; this ends in the formation of a mature fibrous plaque. As plaque is formed, an artery wall gets thicker, resulting in narrowing of the artery’s opening, reducing blood flow and the supply of oxygen to cells. 

In general, atherosclerosis presents no signs and symptoms until it critically narrows or blocks an artery. Some cases, however, may have certain symptoms that mainly depend on the affected arteries:

• Coronary Arteries

If a plaque forms and narrows or blocks the arteries that supply the heart, a disease called coronary heart disease will develop the following symptoms:

• Chest pains, or angina
• Shortness of breath
• Heart attack marked by severe chest pain and pain in the shoulder or arm if the artery is completely blocked

• Carotid Arteries

Carotid artery disease will develop if arteries supplying the brain develop a plaque that narrows or blocks them causing either a stroke or transient ischemic attack (TIA). Symptoms of stroke and TIA include:

• Confusion
• Sudden weakness
• Paralysis or numbness of the limbs
• Loss of balance
• Trouble speaking or understanding speech

• Peripheral Arteries

A Plaque can form in the major arteries supplying the legs, arms, or pelvis causing a disease called peripheral artery disease, which presents symptoms such as:

• Pain or cramping the legs or arms
• Numbness or weakness
• Coldness in the affected limb
• Reduced rate of healing, or nail and hair growth
• Shiny skin or changed skin color in the affected limb
• Weak pulse in the affected limb
• Erectile dysfunction in men

• Renal Arteries

The renal arteries are the arteries supplying the kidneys. Narrowing or blocking of these arteries leads to chronic kidney disease that causes symptoms such as:

• Elevated blood pressure
• Decreased renal function
• Loss of appetite
• Fatigue
• Dry skin
• Easy Bruising
• Feeling thirsty
• Sexual dysfunction
• Muscle cramps

The doctor will take certain steps to establish a diagnosis of atherosclerosis. These steps include:

• Physical exam: The doctor can detect poor blood flow caused by a plaque by listening to the patient’s arteries through a stethoscope. Restricted flow in an artery may present a whooshing sound called a bruit.
• Blood tests: Blood tests are conducted to check levels of certain substances in the blood that may point out to an increased risk of atherosclerosis, such as fats, cholesterol, and blood sugar. 
• Electrocardiogram: It detects and records the electrical activity of the heart to look for any abnormal rhythms that may be caused by atherosclerosis.
• Chest X-ray: Provides a picture of the heart that helps detect signs of heart failure.
• Ankle/brachial Index: It is performed to compare blood pressure in the ankle with that of the arm to detect an imbalance in blood flow. This helps detect peripheral artery disease that may be caused by atherosclerosis.
• Echocardiography: This test uses sound waves to construct a moving picture of the heart to spot areas of poor blood flow to the heart.
• Computed tomography scan: It constructs computer-generated images of the heart and helps in detecting narrowing or stiffness in large arteries.
• Stress test: This test is a group of tests conducted while the person is exercising to increase heart rate. Arteries narrowed by plaque will show decreased blood flow during this test.
• Angiography: This test shows the severity of the blocking of the arteries by using a dye and special X-rays.

There are several treatment options for atherosclerosis that a doctor may follow depending on the case. These options include:

• Lifestyle changes: Lifestyle changes that support heart health include eating a heart-healthy diet, maintaining a healthy weight, doing physical activity, quitting smoking, and managing stress.
• Medications: Statin medications can be used to control or lower cholesterol levels. In addition, anti-platelet medications, beta blockers, angiotensin-converting enzyme inhibitors, calcium channel blockers, and diuretics can be prescribed to manage the condition.
• Medical Procedures: Severe cases of atherosclerosis may require medical procedures or surgical interventions. These may include angioplasty to place a stent in the artery to keep it open, coronary artery bypass surgery to restore blood flow to an obstructed coronary artery, or carotid endarterectomy to remove plaque formations in carotid arteries in the neck.
• Alternative medicine: Some foods and herbal supplements can help reduce high cholesterol and high blood pressure. These include barley, black and green tea, fish oil, garlic, and vitamin C. However, doctor consultation is advised before seeking any of these alternatives.

Atherosclerosis can result in major complications depending on the arteries affected. These complications include:

• Coronary heart disease: This happens when atherosclerosis originates in arteries that supply the heart with oxygen-rich blood.
• Carotid artery disease: When atherosclerosis develops in arteries that supply the brain, the possibility of developing carotid artery disease becomes high.
• Peripheral artery disease: Peripheral artery disease arises when atherosclerosis causes blockage of arteries in the arms or legs, leading to circulation problems.
• Aneurysms: An aneurysm is a bulge in the wall of an artery that can start anywhere in the body and is considered a dangerous complication because it may burst.
• Chronic kidney disease: Narrowing of the renal arteries results in decreased renal function, and eventually kidney failure, which may require dialysis or a kidney transplant.

Adopting a healthy lifestyle is the only known way to prevent atherosclerosis and subsequent diseases. This may include:

• Heart-healthy foods: This includes consuming a variety of fruits and vegetables in addition to beans and peas, fat-free or low-fat milk and dairy products, whole grains, lean meats, poultry without skin, and seafood. Diet should be low in sodium and added sugars.
• Physical Activity: Physical activity can help burn calories and improve fitness level and general health.
• Smoking: Smoking can cause damage and tighten blood vessels and raise the risk for atherosclerosis so it should be avoided.
• Healthy weight: Being overweight increases the risk of a host of diseases including atherosclerosis.

Atherosclerosis may start in childhood and progress slowly. In some people, it may start to progress rapidly in their 30s. Usually, the disease does not become dangerous until people reach their 50s or 60s. Some hardening of the arteries is normal in the process of aging.

There is variation regarding the outlook for atherosclerosis from person to person. Patients diagnosed with atherosclerosis should keep in contact with their doctors to ensure that correct and effective lifestyle changes are taken and that medications are used correctly to lessen the chance of dangerous complications.

Atherosclerosis is a leading cause of vascular disease worldwide. The major clinical manifestations of atherosclerosis include ischemic heart disease, ischemic stroke, and peripheral arterial disease. An article published in the American journal Circulation Research shows that mortality and incidence rates of ischemic heart disease and ischemic stroke have dropped since the middle of the 20th century in high-income countries. As for the majority of low- and middle-income countries, a decline has been observed in mortality from stroke, but mortality from ischemic heart disease remains varied with countries showing declines, while others showing increases.