Hypertension and arterial disease.

There is abundant evidence that the height of an individual's systemic arterial pressure is related, in a graded way, to his chances of developing ischaemic heart disease or cerebrovascular disease. The way in which the link operates in respect of coronary disease is not yet known, and further evidence is required before we can accept that the hypertension is necessarily a direct causal factor rather than a marker of some feature in the individual's make-up which is itself linked to the onset of arterial thrombosis (the ;series' or ;parallel' wiring dilemma). In respect of haemorrhagic stroke not only have we a link but we also have a mechanism of action plus evidence that pressure reduction can modify the risk. We have a ;series' wired circuit, and the problem now facing us is to acquire the wisdom which will allow us to decide when to seek out hypertension and what we should do when we find it.