Hypertension Disease Background

The World Health Organization (WHO) estimated hypertension to occur in 1.28 billion adults aged 30-79 years old and two-thirds of these are living in low- and middle-income countries. About 46% of adults with hypertension are not aware that they have hypertension while about 42% of adults with hypertension are diagnosed and managed.  

The global prevalence of hypertension using the 2017 American College of Cardiology (ACC) and American Heart Association (AHA) definition of hypertension was estimated in 2019 at 1.3 billion. However, most epidemiological data in Asia still utilized the old definition cut-offs of ≥140/90 mmHg.  

The National Health and Morbidity Survey in Malaysia reported that there was an increasing trend in the overall prevalence of hypertension which were 34.6% in 2006, 33.6% in 2011, and 35.3% in 2015 among those ≥18 years old.  

Hypertension remains to be one of the top causes of morbidity and mortality in Asia and although the level of awareness, treatment, and control are steadily increasing, they remain to be low.

Hypertension may be due to multiple factors including neural and chemical disorders, alterations of vascular caliber and elasticity, cardiovascular reactivity, and blood volume and viscosity.

Blood pressure maintenance is complex and involves several physiological mechanisms including arterial baroreceptors, the renin-angiotensin-aldosterone system, atrial natriuretic peptide, endothelins, and mineralocorticoid and glucocorticoid steroids, which together manage the degree of vasoconstriction or vasodilation within the systemic circulation, and the retention of water and sodium to maintain adequate circulating blood volume and dysfunction in any of these processes can lead to hypertension development.

Sympathetic neural activation modulates hypertension by enhancing vasoconstriction and vascular remodeling, producing renal renin via beta 1 adrenergic receptors in the juxtaglomerular apparatus and increasing renal sodium resorption and inflammation.   

Classification of Blood Pressure

The classification must be based on the average of ≥2 properly measured, seated blood pressure readings on each of ≥2 office visits. Various consensus guidelines are available as standard references for the definition of hypertension.¹

BP Classification Based on  2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA*	SBP (mmHg)     DBP (mmHg)
Normal	<120   and   <80
Elevated	120-129   and   <80
Hypertension Stage 1	130-139   or   80-89
Hypertension Stage 2	≥140   or   ≥90

 

BP Classification Based on 2023 ESH**	SBP (mmHg)      DBP (mmHg)
Optimal	<120   and   <80
Normal	120-129   and   80-84
High Normal	130-139   and/or   85-89
Grade 1 hypertension	140-159   and/or   90-99
Grade 2 hypertension	160-179   and/or   100-109
Grade 3 hypertension	≥180   and/or   ≥110
Isolated systolic hypertension (ISH)2	≥140   and   <90

¹Recommendations may vary between countries. Please refer to available guidelines from local health authorities.
*Reference: 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the prevention, detection, evaluation, and management of high blood pressure in adults. This guideline updates prior JNC reports.
**Reference: 2023 European Society of Hypertension (ESH) Guidelines for the management of arterial hypertension. 
²Graded 1, 2, or 3 according to the systolic blood pressure values in the indicated ranges.

Stages of Hypertension

 

• Stage 1: Uncomplicated hypertension (without hypertension-mediated organ damage [HMOD], diabetes, established cardiovascular disease [CVD] or chronic kidney disease [CKD] stage ≥3)
• Stage 2: Presence of HMOD, diabetes, or CKD stage 3
• Stage 3: Presence of established CVD or CKD stage 4 or 5