Systemic hypertension (SHT ) is the commonest clinical entity encountered in cardiology consultations . 95 % of HT is considered primary. The remaining 5 % form the most important class of HT (Secondary to renal parenchymal, vascular , endocrine, etc)
How intelligent is this traditional classification of HT ?
The incidence of primary and secondary HT varies depending upon the level of investigation we do . One of my regular patient who gets to me for HT .He is 42 year old man works in financial institution with lots of work stress and he was marginally obese as well . He was investigated for all known cause of secondary HT and every parameter was found to be normal and was being treated as primary HT.
When he was about to leave my clinic he bowled this google !
Doctor , why do you call mine as primary HT ? . . . When you yourself say my stress and weight is responsible for high blood pressure ?
Valid question is it not ! . . . I told him “somehow” , we have not been taught in medical schools , to consider stress of life as a factor responsible for developing secondary HT !
Final message
Strange definitions in medicine continue . Not every one with high stress levels develop HT .There are some unknown factors operating .Till we know that we will keep calling them as primary HT .
( Who knows the man who raised this question may show up with adrenal hyperplasia or a renal parenchymal dysfunction 5 years down the lane !)
We live by perceived knowledge on a moment to moment basis ! . Ignorance tries to lock the doors of knowledge .
But we continue to open new doors . That is the only purpose of medical research !
A normally functioning circulatory system is vital for our survival . We have about 6000 ml of blood, circulating all over the body in an approximate time of 15-20 seconds.The pressure at which this blood moves across the body is called the blood pressure . Hypertension or simply , high blood pressure is an undesirable hemodynamic disturbance in human circulatory system.Systemic hypertension is the most common type of hypertension. The blood pressure is primarily dependent on the status of the blood vessel(vascular resistance) and cardiac contractility. This regulation is under many neural and hormonal factors.Further the blood pressure varies depending upon the blood vessel calibre, and the local milieu.There is a progressive drop in blood pressure from major arteries to the small arteries .The pressure drop is maximum across the arterioles to reach the venules .The venous circulation has the lowest pressure, it ends up at right atrium with a mean pressure of 0- 5mmhg.
Dr.S.Venkatesan MD 
