This document discusses hypertension (high blood pressure), including its epidemiology, prevention, and control. It begins with learning objectives and defines hypertension. An estimated 1.13 billion people worldwide have hypertension. Prevalence is increasing and it is a major cause of death. Prevention efforts include population-wide strategies like reducing sodium intake and increasing physical activity, as well as high-risk strategies like monitoring blood pressure from childhood. Treatment involves lifestyle changes and medication to control blood pressure. New initiatives in India are screening for hypertension at all levels of the healthcare system.

1. Dr. Abhishek Tiwari,
Assistant Professor,
Department of Community Medicine,
Moti Lal Nehru Medical College, Prayagraj
Epidemiology,
Prevention &
Control of
Hypertension

2. Learning Objectives
To understand why Hypertension is a Public
Health Concern
To understand the Epidemiology of Hypertension
What all should be done to Prevent it ?
Methods available to Control Hypertension ?
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3. Introduction
Hypertension
or elevated blood
pressure - is a
serious medical
condition that
significantly
increases the risks
of heart, brain,
kidney and other
diseases.
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4. Introduction
An estimated 1.13 billion people worldwide have
HYPERTENSION, most of them (2/3rd) living in low &
middle-income countries.
Prevalence 30-40%, 24% in men & 20% women
Prevalence > 60% in people aged >60 years
In 2015, 1 in 4 men & 1 in 5 women had HTN
Annual increase of 15-20% estimated by 2025
A major cause of premature death worldwide.
One of the global targets for Noncommunicable
diseases is to reduce the prevalence of hypertension by
25% by 2025 (baseline 2010)

5. Burden - India
National Family Health Survey 2015-16
11% women and 15% in men were hypertensive
Prevalence was found to be higher in males and
those with high Body Mass Index.
Consistent increase in prevalence with increase in
BMI
Now – health & wellness center are focusing on
Noncommunicable Diseases and their prevention in
particular

6. Hypertension
Blood pressure is the force exerted by circulating blood
against the walls of the body’s arteries, the major blood
vessels in the body. Hypertension is when blood
pressure is too high.
The first (systolic) number represents the pressure in
blood vessels when the heart contracts or beats. The
second (diastolic) number represents the pressure in
the vessels when the heart rests between beats.
If on 2 different days, systolic BP readings on both
days is ≥140 mmHg and/or the diastolic BP readings on
both days is ≥90 mmHg only then we diagnose as HTN

7. Symptoms of HTN
Hypertension is called a "silent killer“
Most people with HTN are unaware of their status as
they have no warning signs or symptoms
It is essential to get blood pressure measured regularly.
When symptoms do occur, they are early morning
headaches, nosebleeds, irregular heart rhythms, vision
changes & buzzing in the ears
Severe hypertension can cause fatigue, nausea,
vomiting, confusion, anxiety, chest pain & muscle
tremors.
The only way to detect hypertension is to measure

8. Grading of HTN
Category Systolic (mm of
Hg)
Diastolic (mm
of Hg)
Optimal <120 And < 80
Normal 120 – 129 And/or 80 - 84
High Normal 130 – 139 And/or 85 - 89
Grade 1 HTN 140 – 159 And/or 90 - 99
Grade 2 HTN 160 – 179 And/or 100 - 109
Grade 3 HTN >= 180 And/or > 110
Isolated systolic HTN >= 140 And < 90
When systolic BP & diastolic BP readings fall in different
category, the higher category should be taken.
Higher the BP higher the risk of Cardiovascular disease.
Extent of organ damage varies in individuals with HTN, hence
it depends on many factors.

9. Measurement
Accurate measurement are essential under
STANDARDIZED conditions for valid comparisons
3 identified source of errors
a) Observer Error – Hearing acuity, interpretation of
korotkow sounds.
b) Instrumental error – e.g. leaking valves, cuffs not
encircling arm etc.
c) Subject errors – physical environment, position,
external stimuli such as fear, anxiety & so on
Sitting position is recommended and a uniform policy
of measurement is essential

10. Classification
Primary [Essential]
Cause unknown, accounts for 90% cases, most
common
Secondary
Some other disease process or abnormality
involved in causation, like kidney disease, adrenal
gland disorder, narrowing of Aorta, toxemia of
pregnancy, altogether less than 10% cases

11. Risk Factors of HTN
The “LIFESTYLE” disease has a range of risk factors
HTN is itself a major risk factor and it has its own risk
factors
NON MODIFIABLE
1) Age – BP increases with age in both sexes due to
accumulation of environmental factors and ageing
phenomenon
2) Sex – in adolescence Men display higher average,
difference is clearly evident in young & adults. Later
on this pattern narrows & may even reverse. Post
menopausal changes are contributory.
.

12. Risk Factors of HTN
NON MODIFIABLE
3) Genetic factors – evidence suggests BP levels are
determined partly by genetic factors, with
polygenic inheritance.
Twin studies - BP of monozygotic twins are strongly
related than zygotic twins. In contrast no relation
was found in levels of husband & wife, and between
adopted children.
Family studies – children of 2 normotensive parents
have 3% possibility of developing HTN, while it is
45% for hypertensive parents
.

13. Risk Factors of HTN
NON MODIFIABLE
4) Ethnicity – Population studies have shown higher
levels in black population
MODIFIABLE
1. OBESITY – Greater the wt. gain greater the risk.
On loosing weight the BP also decreases. “Central
obesity” has been positively correlated with high
BP
2. SALT INTAKE – high intake 7-8 g/day increases
the risk. Low sodium intake decreases the BP.
Japan sodium intake is above 400 mmol/day has
higher incidence
.

14. Risk Factors of HTN
3) SATURATED FAT – It raises BP & serum
cholesterol. Cholesterol & LDL are involved in
atherosclerosis.
Recommended – greater intake of PUFA and less
intake of saturated fat. Fat intake should be less than
30% of total calories.
4) DIETARY FIBRE – beneficial in reducing total
plasma total & LDL cholesterol.
5) ALCOHOL INTAKE – high intake is harmful
.

15. Risk Factors of HTN
6) HEART RATE – hypertensive subjects were found
to have higher heart rate. This may be due to
resetting of sympathetic activity at a higher level
7) PHYSICAL INACTIVITY – minimum of 30 minutes
for at least 5 days a week is essential to reduce
the risk of HTN and NCD. Sedentary lifestyle leads
to obesity and predisposes to NCD
8) ENVIRONMENTAL STRESS – higher noradrenaline
in hypertensive supports that over activity of
sympathetic system is involved
.

16. Risk Factors of HTN
9) SOCIO-ECONOMIC STATUS – earlier higher
disease burden in developed countries, but now
the trend is transitioning. More cases in low &
middle income countries.
10)OTHER FACTORS – most common cause of
secondary HTN is oral contraception, because of
oestrogen
.

17. Rule of Halves
Hypertension is an
“ICEBERG” Disease
Only 1/2 have been
diagnosed
Only 1/2 of those
diagnosed have been
treated
Only 1/2 of those
treated are adequately
controlled
Thus, only
12.5%overall are
adequately controlled

18. Tracking of Blood Pressure
If blood pressure of
individuals were followed up
over a period of years from
early childhood into adult
life, then those whose
pressures were initially high
in distribution, would
continue in the same “track”
as adults.
This phenomenon of
PERSISTENCE is called
tracking & can be applied in
identifying “AT RISK”
children & adolescents.

19. Causes of HTN
A

20. Prevention
WHO recommended approach:
1. Primary Prevention- “all measures to reduce the
incidence of disease in population by reducing
RISK of onset”
a. Population Strategy
b. High Risk Strategy
2. Secondary Prevention
We can control hypertension by medication
(secondary) but the ultimate goal is PRIMARY
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21. Population Strategy- for All
Even a small reduction in average BP of Population
would produce large reduction in incidence of CVD
complications.
GOAL – to shift the BP
towards lower levels
with multifactorial
approach & non
Pharmacotherapeutic
interventions
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Interventions
Nutrition – DASH (dietary
approach to stop HTN), low
sodium & fat
Weight reduction – maintain
BMI < 25
Exercise promotion
Behavioural changes
Health Education
Self Care

22. High - Risk Strategy
GOAL – To prevent the attainment of levels of
blood pressure which requires treatment.
Appropriate for community with low prevalence of
risk factors
Detection of High RISK subjects by assessing all
predisposing factors & clinical methods
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Interventions to identify those at Higher RISK
Tracking of Blood Pressure from childhood
Family History details of hypertension

23. Secondary Prevention
GOAL – To detect & control high BP of effected
individual
1) Early Case detection – major problem, remember
silent killer and iceberg phenomenon. SCREENING
of population with adequate follow up
2) Treatment - modern Anti-hypertensive therapy
3) Patient compliance – “the extent to which the
patients behaviour coincides with clinical
prescription” . Health education improves
compliance
it’s a control and not cure so has to be LIFELONG
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24. Treatment
India
Hypertension
Management
Initiative (in
collaboration
with ICMR)
Measure BP of
all above 30
years
If SBP >= 140
and/or DBP >=
90 mm of Hg
then follow.
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25. Newer initiatives for NCD
Screening at all levels in the health care delivery
system from sub-centre & above
 Capacity building at various levels of health care for
prevention, early diagnosis, treatment, rehabilitation,
IEC/BCC, operational research and rehabilitation.
To support for development of database of NCDs
through Surveillance System and to monitor NCD
morbidity and mortality and risk factors.
Health promotion through behaviour change with
involvement of community, civil society, community
based organizations, media etc.
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26. Thank you all
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