Introduction

Blood pressure is the force created by the heart pump to move blood around the body. Blood carries nutrients and oxygen to all parts of the body. High blood pressure, or hypertension, refers to a condition in which the blood is pumped around the body at a higher pressure.

According to the Singapore National Health Survey (1998), 27.3% of Singaporeans between the ages of 30 and 69 years, suffer from hypertension. It is one of the major risk factors for coronary artery disease and stroke. Untreated hypertension can also cause heart failure and renal failure. Hypertension is the most important risk factor for development of intracerebral bleed.

In general, blood pressure fluctuates with the time of day, physical activity and emotions. Therefore, blood pressure has to be taken under resting conditions and on more than one occasion. Normally, your blood pressure will increase if:
· Your blood volume is increased by too much salt intake which retains more water in the body.
· Your blood vessels become more rigid due to atherosclerosis, a process where fatty substances are deposited in the blood vessel walls.

The different categories for blood pressure is listed below.

Categories of Blood Pressure (BP) Levels in Adults Age 18 Years and Above

	Blood Pressure Level (mmHg)
Category	Systolic BP (mmHg)	Diastolic BP (mmHg)
Normal BP	< 130	< 80
High - Normal BP	130 – 139	80 – 89
Grade 1 Hypertension	140 – 159 *	90 – 99
Grade 2 Hypertension	³ 160 *	³ 100
Isolated Systolic Hypertension*	³ 140	< 90

*Isolated systolic hypertension is graded according to the same level of systolic BP
Source: MOH Clinical Practice Guidelines 2/2005

Risk factors and symptoms

Your blood pressure can be elevated by alcohol consumption, smoking and obesity. You can reduce your risk of getting high blood pressure by keeping your body mass index (BMI) between 18.5 and 22.9 (see below table).

Body Mass Index (BMI) Classification by Public Health Action in Asians
Body mass index = Weight (kg)/ Height (m) x Height (m)

Source: Health Promotion Board

Hypertension usually causes no symptoms, but often leads to the damage of various body organs in the long-term. It is for this reason that high blood pressure or hypertension is referred to as “the silent killer”. Over time, it can lead to damage of the heart and blood vessels, leading to stroke, heart attack or renal failure. Occasionally, when the blood pressure is extremely high, headaches, dizziness or alterations in vision can be experienced.

 

Older people are at a higher risk of developing hypertension. Most of the patients are found to have no cause for the high blood pressure and are categorised as essential hypertension. About 10% of high blood pressure patients have it as a result of kidney diseases or hormonal disorders (secondary hypertension).

Checking your blood pressure

A blood pressure reading of 120/80mmHg is read as “120 over 80 millimetres of mercury”. The top number is your systolic pressure, which is the pressure in your arteries when the heart pumps. The bottom number is the diastolic blood pressure, which is the blood pressure in your arteries when your heart relaxes between contractions.

Normal blood pressure may vary from 90/60mmHg to 120/80mmHg in a young healthy woman. Hypertension is present when a person’s blood pressure is persistently above 140/90mmHg. If you have diabetes or kidney disease, you must strive to maintain your blood pressure at around 120/80mmHg as even marginally higher blood pressure will increase your risk of developing complications.

In most cases, a doctor will use a familiar device called a sphygmomanometer. Some blood pressure testing devices use electronic instruments with digital readouts. In these cases, the blood pressure reading appears on a small screen.

Blood pressure measurements can also be carried out at the convenience of your home. Before you use the equipment, you should first understand the given instructions thoroughly on how to use the device and take readings. You may wish to calibrate your reading with your family doctor. Blood pressure devices are readily available at various healthcare outlets and pharmacies.

Managing high blood pressure

You should check your blood pressure at least once a year. Marginally elevated blood pressure may normalise when you lose weight, exercise more and reduce salt intake.

1. Eat a healthy diet – Avoid foods high in cholesterol and saturated fats such as animal fats, whole milk products, eggs, red meat such as beef and lamb, coconut milk and palm oil. Instead, choose lean meat, fish and low-fat dairy products and increase your intake of fruits and vegetables. Cut back on salty foods as well.

2. Exercise regularly – It is important to exercise at least three times a week. Although there are many kinds of physical activities you could do, walking is one of the best forms of exercise to do. To find out which types of physical activities are suitable for you, check with your doctor.

3. Watch your weight – It has been proven that maintaining a healthy body weight reduces the risks of high blood pressure. To give you a good idea of whether you are keeping a healthy weight, refer to above table.

4. Quit smoking – Smoking can elevate the blood pressure and is also an independent risk factor for coronary artery disease and stroke.

5. Take it easy – To manage stress, engage in regular exercises. Adopt a balanced approach to work and family life. In addition, relax whenever possible to ease the tension whenever feelings of stress arise since stress may aggravate your blood pressure.

If these measures are not successful, then drug treatment maybe needed. However, once medicine has been started, it is essential to continue with the treatment, complemented by a healthy lifestyle. Treatment of hypertension for most people is life-long.