My resting blood pressure is slightly above what doctors define as healthy. 130/90. That is to say, when sitting still, my resting blood pressure is 90 millimeters of mercury, and my pumping pressure is 130 millimeters of mercury. I have a digital blood pressure meter and occasionally take my measurements. During the runup to the election my pressure maxed out at 190/100. I felt stressed, tense, and worried that I would suffer from a stroke or a Victorian fainting episode. Fortunately my doctor tells me that a healthy young person can have episodic pressures up to 240 or above and still be fine. It makes me wonder what my blood pressure is when I go running and my heart is at 170 beats per minute. When I was younger and in much better shape I could get my heart rate up to 210 bpm!
But what do these numbers even mean? Why do we measure blood pressure in millimeters of mercury? It seems so 18th century.
A millimeter of mercury is such an obtuse and ancient measurement of pressure. Liquid mercury is poured into a glass tube. It then falls due to gravity. The space at the top is a vacuum. The inches or millimeters or distance of this vacuum is the "pressure". This was the first method of defining pressure. One could just as easily use water, or any other liquid, and a different distance would be measured. Why the medical community, which prides itself on being modernity itself, continues to use this antediluvian measure of pressure, is very odd.
And again, why do doctors use terms such as systolic and diasystolic? Why not use terms such as “rest” and “pump”? Like everything medical and legal, the origins of these terms are from Latin and Greek. Systolic, which is what doctors use to describe the maximum pressure in the blood vessels during the pumping phase of the heart, is the opposite of diasystolic, which is the minimum pressure of the blood vessels during the period between heartbeats. It derives from the ancient Greek word “sustole”, which means contraction. The modifier “dia” means opposite. Thus the opposite of a contraction is a relaxation, ie “diasystolic”. Why they do not use the word “eirene” or "pasithea", both which could mean “rest” is strange. The word “diasystolic” is very obtuse. It's like saying “I ain't no such thing" which can also be stated as “nope”.
Military organizations and medical organizations share a common characteristic, they are both setup to operate during a crisis. For a hospital, the crisis is of the patient. For a military, the organizational structure is designed to operate itself within the crisis. The patient is itself. The enemy is the disease. Military and medical organizations are both steeped in jargon. However they differ in one dramatic degree. In a military the jargon is created by the lowest ranking members, and works it’s way upwards. In a medical organization, the jargon is created at the top and works it’s way down. The military speaks in the vernacular. The medics speak in Greek and Latin.
To return to blood pressure, what the hell is 100 millimeters of mercury? It’s actually very simple. It’s 1.93 pounds per square inch, or for the non Americans, 13.3 kilopascals. 200 mm/hg is 3.9 psi. 250 mm/hg is 4.8 psi. This latter figure is considered "off the charts" for blood pressure but is surprisingly still fairly low when translated to an industrial terminology.
Why do doctors cling to obtuse Greek terminology and 18th century methods of measurement? I think it’s very simple. They operate on a top down organizational structure. The grunts are not respected, and the poo baa's are in control. In the military the grunt is given great respect, and the officer, while respected, is nonetheless held slightly in contempt, as they are not in the line of fire.
We must respect those who do the actual work. And we must respect the common vernacular. That is my opinion.