Blood Pressure

Blood pressure, name commonly given to arterial pressure, relates to the pressure exerted by blood on the arteries, the vessels by which the heart irrigates the body. It is measured in "Torr" or "mm Hg", and is indicated by two values:

• systolic arterial pressure: peak pressure in the arteries, which occurs near the beginning of the cardiac cycle;
• diastolic arterial pressure: lowest pressure, at the resting phase of the cardiac cycle.

 

Arterial pressure is not static. It may vary from one heartbeat to another, throughout the day, or in response to stress, emotions, physical effort, nutritional factors, drugs, or disease.

 

Normal blood pressure readings corresponding to highest life expectancy according to the Society of Actuaries:

• systolic blood pressure of 98-127;
• diastolic blood pressure of 48-67.

 

Systolic pressure of 140 or higher or diastolic pressure of 90 or higher are currently considered to be indicators of hypertension, which is viewed as a major health hazard.

 

2004 Blood Pressure Guidelines are as follows:

 

Classification of Blood Pressure (BP)

Category	SBP (systolic blood pressure) mm Hg (upper number)		DBP (diastolic blood pressure) mm Hg (lower number)
Normal	< 120	and	< 80
Prehypertension	120-139	or	80-89
Hypertension, Stage 1	140-159	or	90-99
Hypertension, Stage 2	≥ 160	or	≥ 100

 

(National Heart, Lung, and Blood Institute of US Department of Health and Human Services, 2004)

 

  Check areppim's charts for Blood presssure normal & limit values.

New Guidelines: Controversy

By late 2017, the AHA (American Heart Association) issued new guidelines setting normal blood pressure at less than 120 and 80, and the hypertension threshold at 130 over 80, in place of the previous 140 over 90 benchmark. They also established five, instead of the previous four blood pressure ranges as follows:

The new guidelines place a large percentage of the previously healthy population in the hypertension category, possibly requiring medical care and medication. According to Harvard Medical School, this means 70% to 79% of men aged 55 and older previously considered healthy are now classified as having hypertension. Why the change?

In detective stories the sleuth starts the investigation wondering "who benefits from the crime?" As regards the updated blood pressure guidelines, it is clear where the palpable benefit goes. The new benchmarks cause a quantum increase of the numbers of people in need of medical care, which in turn feeds a tremendous revenue stream for the pharmaceutical industry. Knowing how much care the pharma business nourishes for clinicians, contributing generously to their continuing education, clinical trials, research, committee membership, congresses, publications, etc. the least that one should expect is that the latter reciprocate, if only by refraining from doing anything detrimental to the pharma interests. A plain case of good manners.

Be it as it may, the updated guidelines triggered controversy. The American College of Physicians and the American Academy of Family Physicians decided not to endorse them. Among other issues they point out potential conflicts of interest on the AHA authors' part, the fact that they don't offer different recommendations for people younger or older than age 65, their recommendations do not seem to change the overall death rate or quality of life of the patients, and that increasing medication may also raise certain risks, such as fainting and abnormal kidney function.

Accordingly, these societies keep the hypertension thresholds unchanged:

• General population of less than 60 years, at 140 over 90 mm Hg.
• General population older than 60 years, at 150 over 90 mm Hg.

The controversy elicits a dose of skepticism. The trend among standard-setting physicians is to review their recommendations with a downward, one-size-fits-all bias. Blood pressure is just an instance. The bent happens with other ailments such as cholesterol or osteoporosis. By casting the net far and wide, experts substitute a skewed distribution to the standard normal (bell-shaped) distribution of population, thus bringing to life Dr. Knock's famous line: "I don't know of anything but people suffering more or less from illnesses more or less numerous, developing more or less rapidly". Everybody is ill! Or to quote Knock, "every healthy person is an unwary patient". The classic comedy (Knock, or the Triumph of Medicine by Jules Romains) will not unlock the scientific dispute, but will help to smile at it.