Hypertension: Preventive approaches

Normal blood pressure in an adult is 120 mm / 80 mm of mercury (Hg). Here, 120 mm is systolic and 80 mm is diastolic blood pressure. When the systolic blood pressure in an adult is 140 mm of Hg or more and the diastolic blood pressure is 90 mm of Hg or more, then it is called hypertension. In many cases hypertension has got no symptom but it is a major risk factor for stroke (cerebrovascular accident), heart failure, coronary heart disease and renal failure; and thus a major cause of death. Hence hypertension is considered as a ‘silent killer’.

There are many persons in the community who are suffering from hypertension but only a few of them are diagnosed. This diagnosed part can be compared with the small tip of a floating iceberg. On the other hand, a vast majority of hypertensive persons remain asymptomatic for a prolonged period of time and they remain undiagnosed. They can be compared with the huge submerged potion of an iceberg.

Category of hypertension

Hypertension may be categorized as stage 1 and stage 2 hypertension. When the reading of systolic blood pressure is 140-159 mm of Hg or diastolic pressure is 90-99 mm of Hg, then it is categorized as stage 1 hypertension. When the reading of systolic blood pressure is ≥160 mm of Hg or diastolic pressure is ≥100 mm of Hg, then it is categorized as stage 2 hypertension. Reading of systolic blood pressure from 120 to 139 mm Hg or diastolic blood pressure from 80 to 89 mm Hg is called prehypertension.

Types of hypertension

Hypertension may be classified as-

Primary hypertension or essential hypertension, and Secondary hypertension

Primary hypertension or essential hypertension:

In most cases, the causes of hypertension are unknown. When the causes of hypertension are unknown, then it is classified as primary hypertension or essential hypertension. About 90% of all cases of hypertension are primary hypertension or essential hypertension.

Secondary hypertension:

In a few cases of hypertension, the causes are known. When the causes of hypertension are known, then it is classified as secondary hypertension. Important causes of hypertension include: chronic kidney disease, adrenal gland tumours, toxaemia of pregnancy, congenital narrowing of aorta, etc. Causes of hypertension are known in only about 10% of cases.

Risk factors for hypertension

There are some non-modifiable and modifiable risk factors for hypertension.

Non-modifiable risk factors include:

Increasing age: Blood pressure rises as age increases

Sex: In young and middle ages, the blood pressure is slightly higher in males. But in older ages, the pressure may be higher among females.

Genetic factors: Hypertension is more common among children of hypertensive parents. That is, there is a family history of hypertension.

Modifiable risk factors include:

Obesity: Obesity increases the chances of hypertension.

Unhealthy diet: Intake of more saturated fat, consumption of less dietary fibre, more salt intake (more than 5 gm a day) may cause hypertension.

Physical inactivity: Physical inactivity favours hypertension.

Stress, Smoking cigarettes, Alcohol intake, use of oestrogen containing contraceptives- all increase the chances of occurrence of hypertension.

Prevention of Hypertension

Hypertension may be prevented. The World Health Organization (WHO) has recommended two approaches for prevention of hypertension. The approaches are:

Primary prevention, and

Secondary prevention

Primary prevention

Primary prevention means measures to prevent the occurrence of disease in a population. Primary prevention approach includes-

Population strategy, and

High-risk strategy

POPULATION STRATEGY:

Population strategy is directed to the whole population of a community, irrespective of their individual risk levels. Population strategy involves the following interventions:

Proper diet and nutrition:

DASH (Dietary Approaches to Stop Hypertension) is a unique way to prevent high blood pressure. Eating more fruits and vegetables is very essential in this regard. Fruits and vegetables are rich in dietary fibres which are very helpful in preventing hypertension. Further, the diet should contain low fat, especially the saturated fat, cholesterol and total fat. Fat in red meat, egg yolk, cream of milk are rich in saturated fats. Therefore, these foods should be reduced in amount. Instead more whole grain foods and fish can be taken. Poultry can also be consumed. Less salt intake is very beneficial in the prevention of high blood pressure. Not more than 1 tea spoonful salt, which is less than 5 g, is to be taken daily. Extra salt in the form of table salt in the plate or salty fast foods and sauces, etc. are definitely to be avoided. More potassium and calcium in the diet help reduce blood pressure. Banana, oranges, tomatoes, spinach and other dark green vegetables are rich in potassium. Bones of small fish are good sources of calcium. Milk is also a good source of calcium.

Reduction of body weight:

Reduction of body weight is essential to prevent hypertension. It is better to keep the body mass index (BMI) between 18.5 to 24.9 kg/m2.

Promotion of physical activity:

Exercise should be done regularly. Walking for 30 minutes a day for 5 days a week is very much helpful in preventing high blood pressure. Cycling and swimming are also very beneficial.

Behaviour change:

Behaviour change includes living a healthy life style, avoidance of stress, avoidance of smoking and avoidance of alcohol. A healthy life style is the best way to prevent high blood pressure. Smoking, using tobacco in other forms, drinking alcohol, etc. should be avoided. Avoidance of these bad habits will help prevent hypertension.

HIGH-RISK STRATEGY:

Detection of high risk persons by taking family history of hypertension, tracking of blood pressure from childhood, observing the presence of any other risk factors in an individual, etc. may be used to identify individuals at risk. Necessary measures can then be taken to the at risk individuals thus identified.

Secondary prevention

Secondary prevention comprises-

Early detection of cases, and

Providing appropriate treatment to control hypertension

Early case detection can be done by screening the population.

Treatment of hypertension includes drug therapy as well as advice on risk factors such as- reduction of obesity, following a healthy diet, prohibition of extra salt in food, encouraging physical activity, avoidance of stress, avoidance of smoking and avoidance of alcohol intake, etc. Patient compliance is also essential in the treatment of hypertension.

Hypertension: Preventive approaches

Normal blood pressure in an adult is 120 mm / 80 mm of mercury (Hg). Here, 120 mm is systolic and 80 mm is diastolic blood pressure. When the systolic blood pressure in an adult is 140 mm of Hg or more and the diastolic blood pressure is 90 mm of Hg or more, then it is called hypertension. In many cases hypertension has got no symptom but it is a major risk factor for stroke (cerebrovascular accident), heart failure, coronary heart disease and renal failure; and thus a major cause of death. Hence hypertension is considered as a silent killer. There are many persons in the community who are suffering from hypertension but only a few of them are diagnosed. This diagnosed part can be compared with the small tip of a floating iceberg. On the other hand, a vast majority of hypertensive persons remain asymptomatic for a prolonged period of time and they remain undiagnosed. They can be compared with the huge submerged potion of an iceberg. Category of hypertension Hypertension may be categorized as stage 1 and stage 2 hypertension. When the reading of systolic blood pressure is 140-159 mm of Hg or diastolic pressure is 90-99 mm of Hg, then it is categorized as stage 1 hypertension. When the reading of systolic blood pressure is 160 mm of Hg or diastolic pressure is 100 mm of Hg, then it is categorized as stage 2 hypertension. Reading of systolic blood pressure from 120 to 139 mm Hg or diastolic blood pressure from 80 to 89 mm Hg is called prehypertension. Types of hypertension Hypertension may be classified as- Primary hypertension or essential hypertension, and Secondary hypertension Primary hypertension or essential hypertension: In most cases, the causes of hypertension are unknown. When the causes of hypertension are unknown, then it is classified as primary hypertension or essential hypertension. About 90% of all cases of hypertension are primary hypertension or essential hypertension. Secondary hypertension: In a few cases of hypertension, the causes are known. When the causes of hypertension are known, then it is classified as secondary hypertension. Important causes of hypertension include: chronic kidney disease, adrenal gland tumours, toxaemia of pregnancy, congenital narrowing of aorta, etc. Causes of hypertension are known in only about 10% of cases. Risk factors for hypertension There are some non-modifiable and modifiable risk factors for hypertension. Non-modifiable risk factors include: Increasing age: Blood pressure rises as age increases Sex: In young and middle ages, the blood pressure is slightly higher in males. But in older ages, the pressure may be higher among females. Genetic factors: Hypertension is more common among children of hypertensive parents. That is, there is a family history of hypertension. Modifiable risk factors include: Obesity: Obesity increases the chances of hypertension. Unhealthy diet: Intake of more saturated fat, consumption of less dietary fibre, more salt intake (more than 5 gm a day) may cause hypertension. Physical inactivity: Physical inactivity favours hypertension. Stress, Smoking cigarettes, Alcohol intake, use of oestrogen containing contraceptives- all increase the chances of occurrence of hypertension. Prevention of Hypertension Hypertension may be prevented. The World Health Organization (WHO) has recommended two approaches for prevention of hypertension. The approaches are: Primary prevention, and Secondary prevention Primary prevention Primary prevention means measures to prevent the occurrence of disease in a population. Primary prevention approach includes- Population strategy, and High-risk strategy POPULATION STRATEGY: Population strategy is directed to the whole population of a community, irrespective of their individual risk levels. Population strategy involves the following interventions: Proper diet and nutrition: DASH (Dietary Approaches to Stop Hypertension) is a unique way to prevent high blood pressure. Eating more fruits and vegetables is very essential in this regard. Fruits and vegetables are rich in dietary fibres which are very helpful in preventing hypertension. Further, the diet should contain low fat, especially the saturated fat, cholesterol and total fat. Fat in red meat, egg yolk, cream of milk are rich in saturated fats. Therefore, these foods should be reduced in amount. Instead more whole grain foods and fish can be taken. Poultry can also be consumed. Less salt intake is very beneficial in the prevention of high blood pressure. Not more than 1 tea spoonful salt, which is less than 5 g, is to be taken daily. Extra salt in the form of table salt in the plate or salty fast foods and sauces, etc. are definitely to be avoided. More potassium and calcium in the diet help reduce blood pressure. Banana, oranges, tomatoes, spinach and other dark green vegetables are rich in potassium. Bones of small fish are good sources of calcium. Milk is also a good source of calcium. Reduction of body weight: Reduction of body weight is essential to prevent hypertension. It is better to keep the body mass index (BMI) between 18.5 to 24.9 kg/m2. Promotion of physical activity: Exercise should be done regularly. Walking for 30 minutes a day for 5 days a week is very much helpful in preventing high blood pressure. Cycling and swimming are also very beneficial. Behaviour change: Behaviour change includes living a healthy life style, avoidance of stress, avoidance of smoking and avoidance of alcohol. A healthy life style is the best way to prevent high blood pressure. Smoking, using tobacco in other forms, drinking alcohol, etc. should be avoided. Avoidance of these bad habits will help prevent hypertension. HIGH-RISK STRATEGY: Detection of high risk persons by taking family history of hypertension, tracking of blood pressure from childhood, observing the presence of any other risk factors in an individual, etc. may be used to identify individuals at risk. Necessary measures can then be taken to the at risk individuals thus identified. Secondary prevention Secondary prevention comprises- Early detection of cases, and Providing appropriate treatment to control hypertension Early case detection can be done by screening the population. Treatment of hypertension includes drug therapy as well as advice on risk factors such as- reduction of obesity, following a healthy diet, prohibition of extra salt in food, encouraging physical activity, avoidance of stress, avoidance of smoking and avoidance of alcohol intake, etc. Patient compliance is also essential in the treatment of hypertension.