What is atherosclerosis?‏

What is atherosclerosis?

Atherosclerosis is a potentially serious disease in which the medium and large arteries of the body become blocked because of fatty substances like cholesterol. These substances are called atheromas or plaques.

Arteries

The circulatory system is composed of arteries and veins. Blood is pumped from the heart through the aorta (the main artery connected to the heart) before traveling through smaller arteries that branch off from each other. The blood passes into small blood vessels, known as capillaries, in which the oxygen is transformed into the cells of the body tissues and organs. The blood returns to the heart through the veins. Hardening and narrowing of the arteries is potentially dangerous for two reasons:

• Restricted blood flow can damage an organ and block its correct functioning
• If a plaque breaks it can cause a clot at the point of the rupture, which can in turn block the blood supply to a major organ like the heart, causing a heart attack, or the brain, causing a stroke

Cardiovascular Diseases

Atherosclerosis is a major risk factor for many diseases that affect blood circulation. These diseases are known as cardiovascular diseases, among them are:

• Peripheral arterial disease: where the blood supply to the legs is blocked, causing muscle pain
• Coronary heart disease: where the main arteries supplying the heart (the coronary arteries) become blocked with plaque
• Stroke: a very serious disease in which the blood supply to the brain is interrupted
• Heart attack: a very serious disease in which the blood supply to the heart is blocked

What are the symptoms of atherosclerosis?

Atherosclerosis usually shows no symptoms until the blood circulation is not obstructed or blocked, leading to the onset of cardiovascular disease. The type of cardiovascular disease and associated symptoms depend on where the blocking occurs. The diseases caused byatherosclerosis include:

• Peripheral arterial disease
• Angina
• Aneurysm
• Heart attack
• Stroke

Peripheral arterial disease

Peripheral arterial disease, also known as peripheral vascular disease, is a disease that occurs when there is a blockage in the arteries of the limbs (in most cases, in the legs). The most common symptom of peripheral arterial disease is a pain in the legs, typically occurring in one or both thighs, hips or calves. The pain can appear as a cramp, or a feeling of weakness or heaviness in the muscles of the legs, it can come and go and usually worsens with exercise, such as when walking or climbing stairs. Physical exertion increases the need for more blood in the muscles, but because the arteries are too narrow, this request cannot be satisfied which causes the onset of pain. Other symptoms of peripheral arterial disease include:

• Fatigue or numbness in the legs
• Pain in the feet or legs that does not disappear
• Change in the color of the legs
• Loss of hair on the legs
• Thickening of the toenails
• Erectile dysfunction, also known as impotence (in men)

Angina

Angina is similar to peripheral arterial disease and is caused by reduced blood supply to the heart. The most common symptom of angina is a sensation of pain or discomfort in the chest. The pain may be thick, dull or intense and generally disappears within minutes. The pain that is associated with angina can spread from the chest to the left arm, neck, jaw and back, and generally follows physical activity or emotional stress. In some cases, the pain can develop when the temperature is cold or after eating. Some people may also have the following symptoms:

• Difficulty in breathing
• Nausea
• Fatigue
• Dizziness
• Belching
• Agitation

The onset of symptoms of angina is often called an angina attack.

Aneurysm

Atherosclerosis weakens the walls of blood vessels and can lead to the formation of an aneurysm (a bulge in a blood vessel). If the aneurysm is enlarged, there is a danger that it can break, causing a potentially fatal internal bleeding or organ damage. An aneurysm can develop anywhere in the body, but there are two common types:

• Intracranial aneurysm (also known as cerebral aneurysm) that develops within the brain
• Aortic aneurysm that develops within the aorta (the large blood vessel that runs through the abdomen and carries blood out of the heart)

If the aortic aneurysm ruptures, you may experience a sudden and intense pain in the center or the side of the abdomen. In men, the pain may also radiate into the scrotum (the pouch that is located between the legs containing the testicles). The rupture of an intracranial aneurysm usually begins with a sudden, severe headache, described as a blow to the head, which becomes an excruciating pain never felt before.

Heart Attack

If one of the plaques in the coronary arteries is broken, it could create a blood clot that can block the blood supply to the heart, causing a heart attack. The symptoms of heart attack include:

• Chest pain, which is generally located at the center of the chest and can feel like a pressure or compression
• Pain in other parts of the body as if it was traveling from the chest to the arms (usually the left arm, although it can strike both arms), jaw, neck, back and abdomen
• Overwhelming sense of anxiety
• Difficulty breathing
• Nausea
• Confusion
• Coughing
• Vomiting
• Wheezing

Apoplectic stroke

A blood clot can also block the blood supply to the brain, causing a stroke. The main symptoms of a stroke can be seen from a certain expression on the face (as it may fall on one side, the person may not be able to smile, his mouth or his eye might fall), arms (because of weakness the person may not be able to raise their arms or keep them there), language (the person might mumble instead of speaking).

Other symptoms include:

• Dizziness
• Communication problems
• Difficulty in chewing
• Severe headaches
• Numbness or fatigue that can lead to a complete paralysis of one side of the body
• Loss of consciousness

There is also a disease related to stroke, known as transient ischemic attack, in which the blood supply to the brain is temporarily interrupted, causing a small stroke. The transient ischemic attack symptoms are the same as those of a stroke, but they last from a few minutes to a few hours before disappearing completely. However, a transient ischemic attack should not be ignored as well as a serious sign that should suggest problems related to the contribution of blood to the brain.

Who is affected by atherosclerosis?

It is difficult to calculate how common atherosclerosis may be, because it does not cause visible symptoms until it reaches an advanced stage and causes the onset of age-related diseases, such as a heart attack. However, it is believed that almost all adults haveatherosclerosis to some degree. Atherosclerosis is more common among people over 40 years of age and more common among men than women, perhaps because the hormones used in the female reproductive cycle (such as estrogen) are a protection against the disease. Risk factors that can greatly accelerate the process of atherosclerosis include:

• Smoking
• High-fat diet
• Little exercise
• Being overweight or obesity
• Having diabetes, both type 1 and type 2
• High blood pressure (hypertension)

What are the causes of atherosclerosis?

As you get older, the arteries harden and narrow, leading to atherosclerosis, however, there are many factors that can seriously speed up this process.

Diet rich in fat and cholesterol

Cholesterol is a type of fat essential for the proper functioning of the body. Cholesterol contributes to the production of hormones, the formation of membranes (the walls that protect individual cells) and the protection of nerve endings. There are two types of cholesterol:

• Low-intensity lipoprotein: composed mainly of fat, less protein. This type of cholesterol can clog arteries and is called bad cholesterol
• Lipoprotein high intensity: mainly composed of protein, plus a small amount of fat. This type of cholesterol can help reduce the block into the arteries, and because of this it is called good cholesterol

The majority of cholesterol the body needs is produced by the liver. However, if you eat foods high in saturated fat, the fat breaks down into bad cholesterol. Foods high in saturated fat include:

• Biscuits
• Cakes
• Bacon
• Sausage
• Canned meat
• Butter
• Cream

Bad cholesterol is attached to arterial walls in the form of fat deposition which, over time, gradually restricts or completely blocks the blood supply. Fat deposits are also known as plaques or atheromas. In addition to a high fat diet, lack of regular exercise, being obese and drinking excessive amounts of alcohol may enhance the increase of bad cholesterol in the body. The medical term for the presence of high levels of cholesterol is hyperlipidemia.

Smoking

Smoking can damage the walls of arteries. If the arteries are damaged, the blood cells, called platelets, are trying to repair the damage, causing a narrowing of the arteries. Smoking can also diminish the ability of the blood to carry oxygen throughout the body, increasing the possibility of a blood clot forming.

High blood pressure

High blood pressure (hypertension) can damage the arteries in the same manner smoking does. The arteries are involved in pumping the blood at a certain pressure. If this pressure is too high, the walls of the arteries are damaged. High blood pressure can be caused by:

• Being overweight
• Intake of excessive amounts of alcohol
• Stress
• Smoking
• Lack of exercise

Diabetes

If you are suffering from diabetes type 1 or type 2, and it is not properly controlled, the excessive amount of glucose in the blood can damage the walls of the arteries.

Obesity

Being overweight or obese increases the risk of developing atherosclerosis and cardiovascular disease directly, and can also lead to related risk factors. In particular, people who are overweight or obese:

• Have an increased risk of developing high blood pressure
• Tend to have higher levels of cholesterol resulting from a diet rich in fat
• Have an increased risk of developing type 2 diabetes

Lack of exercise

Being overweight or obese and the lack of exercise are not directly correlated with an increased risk of atherosclerosis and cardiovascular disease. However, they are linked to an increased risk of being overweight, obesity and having high blood pressure (hypertension).

Alcohol

Drinking too much alcohol can cause high blood pressure (hypertension) and increase the levels of cholesterol in the blood, which increases the risk of developing atherosclerosis and cardiovascular disease. Those who drink frequently also tend to have other unhealthy habits like smoking, a diet rich in fat and not doing enough exercise.

Family Medical History

If you have a first degree relative (parent, brother or sister) suffering from atherosclerosis or cardiovascular disease, it is twice as likely that you will develop similar problems than the general population.

Ethnicity

The percentage of people with high blood pressure and diabetes is greater among those of African and Afro-Caribbean descent, which means that in these groups there is a higher risk of developing atherosclerosis and cardiovascular disease.

Pollution

Researches found that people who live in very polluted areas tend to have more chance of developing atherosclerosis.

How is atherosclerosis treated?

The treatment for atherosclerosis is aimed at preventing the worsening of the disease, which could otherwise lead to a heart disease or a heart attack. This objective can be achieved using a combination of lifestyle changes, like eating healthy and drug treatment.