Understanding Hypertension (High Blood Pressure)


What is blood pressure?

This is the pressure of blood in your arteries, measured in millimeters Mercury (mmHg). The systolic top reading (systolic pressure) is the pressure at which blood is pumped around your body when your heart beats and the bottom reading (diastolic pressure), is the residual pressure in the system while your heart relaxes and fills up with blood. Normal blood pressure varies greatly, but is accepted as levels below 140/ 90 mmHg.

Why is blood pressure important? 

Hypertension is diagnosed when the blood pressure is elevated consistently above 140/90mmHg. This increases the chance of developing hardening of the arteries which may lead to strokes, heart and kidney problems. As blood pressure varies greatly through the day, a single, slightly high reading is not always a cause for concern. Some people may get “white coat” hypertension when visiting their doctor and  home blood pressure monitoring may be useful to exclude this.

What causes high blood pressure?

In most people with hypertension, the exact cause is unknown and this is known as essential/primary hypertension. Few people have secondary hypertension, which may be due to kidney or hormonal problems. Hypertension can affect anyone, but is more common in people with a family history of hypertension.

Lifestyle factors such as being overweight, excessive dietary salt intake, excessive alcohol consumption and a sedentary lifestyle, are all likely to increase your blood pressure. These factors, unlike your family history, are all modifiable.

What are the symptoms of high blood pressure? 

Since it usually causes no symptoms, hypertension is often called the “silent killer,” but a few people with high blood pressure may notice headaches, dizziness and nose bleeds. Low blood pressure is not generally important in otherwise healthy people with no symptoms.

What investigations may be needed? 

Your doctor will take a personal and family history from you and give you a physical examination. You should also have urine and blood tests to check for any kidney problems or other causes of secondary hypertension. You may require an ECG (electrocardiogram), which checks the electrical activity of the heart and may show changes if your blood pressure has been elevated for some time.

Increasingly, home monitoring is used to assess whether blood pressure elevations are sustained. Good quality digital home blood pressure monitors are accurate if used correctly and it is often useful to take a written record of your blood pressure readings when you visit your doctor.

How can hypertension be treated? 

Unless your blood pressure is extremely high when hypertension is diagnosed, the initial treatment is through lifestyle modification. Weight loss, taking more regular exercise and cutting down on salt and alcohol intake may all help to reduce blood pressure.

The incentives to achieve these lifestyle changes should be great since, apart from lessening the possibility of heart attacks or strokes, the other alternative is drug treatment.

Once the decision is made that you need drugs it is likely that these will have to be continued for many years, if not for life. Modern hypertension drugs are effective and safe, but most people would prefer to try to control their lifestyle than start long-term medication.

When does medication become necessary? 

If lifestyle modification proves difficult to achieve, or does not reduce blood pressure adequately or quickly enough, medication becomes necessary. There are many different types of anti-hypertensive drugs and the initial choice depends on several factors, which your doctor should discuss with you.

Your response to the medication and the occurrence of side effects require close initial monitoring. Whichever medication you are on, it is still important that you continue to modify your lifestyle as mentioned above. Low dose aspirin and statin treatment to lower cholesterol may also be recommended if your doctor thinks you have a high risk of heart disease or stroke.

Does smoking contribute to hypertension? 

Smoking has no direct effect on blood pressure but, like high cholesterol, is an important risk factor in heart disease and stroke. Smoking increases the amount of narrowing in your arteries and stopping smoking will reduce your chance of a heart attack by 50% in the first year.

Does alcohol contribute to hypertension? 

Regular, heavy drinking my elevate your blood pressure to be too high and more difficult to control if you are on medication. The recommended maximum weekly intake of alcohol is 21 units for men and 14 units for women (one unit is equivalent to ½ pint of beer, a small glass of wine or a single tot of spirits.) This should be spread over the week and binge drinking should be avoided.

Can dietary modification help? 

You should eat at least 5 portions of fruit and vegetables every day and reduce your salt intake. Fruit and vegetables are a good source of fibre and also of potassium, which has the opposite effect of salt and may help reduce your blood pressure. They are also high in anti-oxidants, which may help prevent heart disease.

You should reduce your salt intake to about 6 grams a (one teaspoonful) a day. Most people eat at least 12 grams daily and this has a direct effect on blood pressure. At least ¾ of the salt we eat is “hidden” in processed foods and you should cut down on these and always read the labels.

Food high in salt includes crisps and other salty snacks, bread, breakfast cereals, processed meats, soups, sauces and pre-prepared and instant meals.

[stextbox id=”warning” shadow=”true” color=”ff0000″]WW TIP: Foods high in Magnesium such as spinach and almonds can help reduce blood pressure by relaxing (widening) arteries.[/stextbox]

Will exercise and weight loss help? 

Being overweight increases blood pressure and may lead to other health problems such as diabetes, heart disease and some cancers. Weight reduction by dieting and regular exercise is essential to the management of hypertension and may prevent or postpone the need to take medication. Guides to a healthy weight are BMI (body mass index, calculated from your height and weight), abdominal circumference and % body fat.

Weight is best achieved by reducing the number of calories consumed and burning off more calories by exercise. Crash diets or meal replacements are usually difficult to sustain and it is better to begin a healthy diet and aim for a target of about 1 lb (½ kg) per week. Weight lifting and vigorous sports such as squash are not advised if you have hypertension and if you are very overweight you should check with your doctor before starting an exercise programme.