Blood Pressure

Manawatu Times, Volume 64, Issue 161, 11 July 1939, Page 4

Blood Pressure

It is probably only in the last 20 or 30 years that the term blood pressure has become generally familiar, and, indeed, it had not loomed very largely in the medical world much before that time, although it had been a subject of investigation and experiment in tho laboratories of physiologists.

In practice, blood pressure is usually expressed in terms of a column of mercury attached to a receptacle contain* ing air, which is wrapped round the arm.

Tho tension in this receptacle is increased by pumping in more air up to a point at which the pulse is obliterated and can no longer bo felt. The reading on the mercury scale is then noted and is described as the systolic blood-pres-sure.

Tho tension in the receptacle is then slowly reduced to a point at which, by listening through a stethoscope over the obliterated blood-vessel, a characteristic sound associated with returning circulation is heard; and the reading on the scale iB again noted and described as the diastolic blood pressure. For a considerable time it was generally held by cardiologists and others that tho systolic figure was the more significant. Later it was believed by many that the diastolic figure was probable a more accurate index of whatever blood-pressure, thus recorded, represent* ed. At the present moment it would probably be true to say that opinion is divided.

There has been similar considerable divergencies of opinion as to what, at any age, should be regarded as a “normal” blood pressure; and an immense amount of work has been done, and is still in progress, upon the whole subject.

Thus large-scale observations amongst apparently healthy and active young men have revealed in many of them blood-pressures far higher than were, at once time, regarded as “normal.” It has also been shown that bloodpressure may be enormously influenced by emotions such ns anger or fear, or event the excitement of having it taken, and to arrive at any sort of reasonable estimation of the blood-pressure of any particular person, the mean of two or three or more readings, taken in quiet and accustomed circumstances, should preferably be the method adopted. Even so, it has become clear that very wide variations seem to be compatible with normal health and longevity; and, indeed, persons with what, at one time, would have been considered perilously high blood-pressures have been observed to lead strenuous lives for many years with such pressures. Unless, therefore, a high blood-pres-sure, or a relatively low blood-pressure, is definitely associated with accompanying signs of ill-health, it is probably tho wisest court not to pay too much attention to them.

Should a very high blood-pressure bo associated with severe or chronic headache or giddiness, or a very low pressure with undue languor and mental depression, appropriate measures can be taken, the former being probably the more serious condition. It is also the commoner of the two; and in such cases violent exercise should be avoided, the diet should be light, and largely vegetarian, alcoholic drinks should be avoided, and generally a regime of allround temperance adopted. Such measures are probably far more effective than any treatment, at present known, by drugs, in relieving the associated strain on organs, such as the heart and kidneys. But it should be remembered by the more apprehensive that what is known as essential or malignant hypertension, or really serious blood-pressure, is, happily, a not very common condition.