You are really not understanding my point. I'm not trying to be insulting, but you are just not following what I am saying and you're clearly arguing a different point than I am arguing.
First off, you are talking about a diagnosis
of hypertension. That, obviously, isn't an exact science because, as you noted, diagnostic criteria is subject to change.
I am talking about the actual measurement of ones blood pressure. You know, wrap thing around someones arm, inflate it, blah blah blah. That wasn't around 100 years ago, and it is an example of a scientific advancement in the field of medicine. If done properly, it tells you, within a slim MOE, what your BP is at the time. Very objective data. And it is highly reproducible. Likewise for blood assays for lipids, glucose, etc. They all utilize scientific principles to give you information which wasn't really attainable (at least not as readily and easily) not too long ago.
MrCarton said it best with this:
I think the point is that science has allowed us to quantify blood pressure, the "practice" of medicine uses that information to predict and treat disease. As our understanding (scientific knowledge) increases the treatments and perception of the data change with it (medical practice). It isn't always a linear progression, which leads some people to describe medicine as an art.
I hope that clears up what I was saying when I brought up BP, high cholesterol, etc