What is atherosclerosis?

Atherosclerosis is a disease in which a characteristic lesions in the wall of the arteries are developed, called "atheromas", which are formed by the accumulation of fat, especially cholesterol, white cells infiltrate, smooth muscle cells of the artery wall, and scar tissue.

Atherosclerosis plaques tend to grow over time and gradually clog the arteries. These plaques can appear in any artery of the body, but are most common in coronary, cerebral, and lower extremity arteries.

Ischemic heart disease is the most frequent cardiovascular disease and the most common cause of death in industrialized countries. About 30% of deaths in these countries are caused by coronary artery disease. The usual cause of coronary artery disease is atherosclerosis.


What are the causes of atherosclerosis?

The precise causal mechanism of atherosclerosis is not well known. Through epidemiological studies it has been possible to relate atherosclerosis with various risk factors, although the exact mechanism by which these factors produce atherosclerosis is unknown. However, it is shown that the control of these risk factors decreases the incidence and severity of atherosclerosis and its complications.

The atherosclerosis has been linked with a number of predisposing factors or cardiovascular risk factors. The concept of risk factors for atherosclerosis comes from several epidemiological studies in which a causal relationship between these factors and ischemic heart disease was established.

Risk factors of ischemic heart disease that have been well established are smoking, hypertension, hyperlipoproteinemia, diabetes mellitus, male sex, advanced age, and family history. Several other minor risk factors have been linked to atherosclerosis, including the excessive intake of saturated fat, hypertriglyceridemia, hyperuricemia, obesity, stress, and physical inactivity.



Atherosclerosis is characterized by the development of lesions in the arteries ranging from an initial phase, in which fat deposits are observed in the arterial wall, to more advanced lesions, in which besides fatty infiltration, can be found cell proliferation, thrombotic material, scar tissue, and calcification.

Several theories have been proposed to explain the cause of these lesions. The most widely accepted theory is that the blood cholesterol enters the artery wall, which is followed by the entry of white blood cells. These are loaded with lipid deposits and transformed into so-called “foam cells”.

These changes induce proliferation of smooth muscle cells of the arterial wall. All this leads to an infiltrate in the artery wall composed of fat, white cells, and smooth muscle cells, forming the atherosclerotic plaque.

AtherosclerosisAnother theory proposes that the risk factors of atherosclerosis (smoking, cholesterol, diabetes, hypertension, etc.) cause changes in the arterial wall leading to infiltration of white blood cells and subsequently to the fat deposit and cell proliferation.

Some believe that the process is actually the result of an autoimmune inflammatory response because the injury caused by risk factors induces the reaction of white blood cells against arterial wall.

An alternate explanation of the causal mechanism of atherosclerosis is the infection theory, derived from studies in which microorganisms were detected in arterial lesions. Infection by a number of different organisms has been associated with the development of atherosclerosis in several studies. These infections could act directly producing arterial lesions or triggering an autoimmune response against the arterial wall.



What are the consequences of atherosclerosis?

Although many atherosclerotic lesions progress slowly, some do so very quickly, which appears to be due to the early plaque rupture. The plaque rupture may result in thrombosis on its surface and / or intraplaque hemorrhage. Sometimes this causes severe acute arterial narrowing or occlusion and the corresponding associated ischemic syndrome (unstable angina or myocardial infarction).

In others, however, the plaque fissure and its consequences are not very important, but account for lesion growth. In this way, small and repeated plaque fissures can lead to progression of atherosclerosis and increase the arterial stenosis, which may present with symptoms or not.


best acne treatment                   muscle mass