This slow degenerative disease of arteries is our major health hazard
today. It accounts for a quarter million deaths from heart attacks and strokes
each year in Britain.
Patchy deposits of fatty material are laid down within the inner lining
of the arteries. As a result (i) arteries get furred up, and narrowed, (ii) the
normally smooth inner surface of the artery may crack, which causes the
blood to clot (thrombosis) just as it does following an external wound, or
(iii) the arterial wall is weakened, gives way and bleeds (hemorrhage).
When atheroma affects the coronary arteries it causes angina, heart attacks,
or sudden death. When it affects the arteries to the brain it causes strokes.
When it affects the leg arteries it causes pain and limping (claudication).
Atheroma builds up silently for many years before it causes trouble.
We now realise, though, that atheroma is not at all an inevitable
consequence of getting old. Ideed the tragedy is that it claims so many in
the prime of life. Research has not yet revealed exactly how atheroma
occurs, but we do know that it is more likely to occur (i) if you smoke, (ii) if
it runs in the family (iii) if you have high blood pressure, and probably (iv)
if you eat too much fat, weigh too much and take too little regular exercise.
It is also more likely to occur if (v) you have diabetes, or (vi) have high
blood levels of cholesterol. Circumstances known to make heart attacks or
strokes more likely are known as ‘risk factors’. Obviously there is much
that can be done to prevent the chances of a heart attack or stroke.
Importantly there is much that we can do for ourselves if we start in time. 
The deterioration of a normal artery (left) is seen as atheroma
develops and begins depositing fatty substances and roughening
the channel lining (centre) until a clot forms (right) and plugs the
artery to deprive the heart muscle of vital blood and oxygen which
results in a heart attack.