Atherosclerosis
Atherosclerosis describes the process by which damage to the artery wall leads to 'furring up' of the artery.
This is the result of damage to the delicate inner lining (endothelium) of the artery by certain risk factors:
 |
age - arterial disease increases with age. |
|
smoking - especially cigarettes but also pipes and cigars if the smoke is inhaled. Smoking doubles the risk of a heart attack and of stroke (in patients with high blood pressure), and massively increases aggravates the progression of complications of peripheral arterial disease. The number of cigarettes smoked is less important than the mere fact of smoking. |
|
high blood pressure - most vascular disease is associated with mild hypertension (high pressure) because it is so common. The risks of disease are rapidly reversed by controlling the pressure. |
|
diabetes |
| high cholesterol - the main culprit is low density lipoprotein (LDL) cholesterol. The overall cholesterol level is a good guide to LDL cholesterol levels. Ideally it should be around 5 mmol/l or less. |
|
genetic factors - a family history indicates this. Men are more affected than women although the risks increase for women as they grow older. |
Combining these risk factors increases the risks of atherosclerosis significantly.
The figure shows what happens in the artery wall. Initially fatty streaks appear - these are very common at an early age and some may go away if there are no other damaging influences.
With time and on-going damage of the endothelium, cells from the blood stick to the damaged areas - these are the platelets. Various factors from platelets, white blood cells and the blood plasma make the muscle cells in the artery wall increase in number. Cholesterol accumulates in these cells causing more damage and further narrowing of the artery. Some of the muscle cells die forming a collection of cholesterol and dead cells (this is the atheromatous plaque). Calcium may be deposited in the artery wall at areas of damage and these areas become scarred forming atherosclerotic plaques.
The tissues beyond the narrowing are deprived of a full blood flow - this is known as ischaemia.
The symptoms this process causes depends on where the narrowing occurs - in the heart arteries it may cause angina, in the leg arteries it may cause intermittent claudication or critical ischaemia and in the neck arteries it may cause mini-strokes (TIAs).
Atherosclerotic plaques can crack causing the blood to clot at that point. This may present as a heart attack, stroke, sudden worsening of the symptoms in the legs or death.
The body may be able to dissolve the clot and the situation may revert to an atherosclerotic plaque - usually with more narrowing of the artery.
Instead of narrowing the artery, the above processes may cause the artery to become weakened so that it balloons out - this is called an aneurysm.
These changes to not occur in the veins as they are not exposed to the high blood pressures that the arteries are.
For advice on lifestyle changes to tackle atherosclerosis, click here.
Press 'Back' on your browser