What are 4 major causes of high blood pressure?

Man getting a blood pressure check

Blood pressure is an important indicator of your overall health and wellbeing. High blood pressure — which is also known as hypertension — is the leading risk factor for heart disease and stroke. It also increases your risk of kidney disease, diabetes, eye disease and erectile dysfunction.

High blood pressure is a measure of the pressure exerted on the walls of the arteries as blood is pumped around your body. It varies according to activity, stress levels, exercise and sleep. If your blood pressure is higher than normal most of the time, then your doctor may diagnose you with hypertension.

Blood pressure has two measurements and everyone’s reading is different. The top number is called the systolic pressure (when the heart beats), while the bottom number is known as the diastolic pressure (when the heart muscle is relaxed).

Your blood pressure is considered to be “high” if the systolic pressure (the higher number) is 140 or greater, or the diastolic pressure (the lower number) is 90 or higher, or both.

Your doctor will discuss with you what he or she considers to be normal for you based on your age, family history and other health factors.

What causes high blood pressure?

While there is no single cause of hypertension, there are a number of risk factors that can predispose you to high blood pressure. Some of these you can influence and improve through lifestyle changes, and others we can’t.

Top 5 causes of high blood pressure – and what to do about it

1. Age and family history

The risk of high blood pressure increases as we age. Between 40-50% of Australians over the age of 70 live with hypertension. Also, if a member of your family has high blood pressure, then you are at increased risk as well.

Action: Speak to your doctor about your family history, and ensure you have regular blood pressure checks. Also consider whether you have any other risk factors for hypertension that you can improve through healthy lifestyle changes.

2. Sedentary lifestyle

People who don’t get enough exercise tend to have higher blood pressure. About 45% of people aged 18–64 and 59% of people aged 65 and over don’t get enough physical activity, which puts us at greater risk of developing chronic health conditions, including high blood pressure.

Action: Be active for at least 30 minutes every day. If it’s been a while since you’ve engaged in regular exercise, then get the all-clear from your doctor first.

3. High salt intake

A diet high in salt is a risk factor for high blood pressure. National guidelines recommend consuming no more than one teaspoon of salt per day. However, the average person consumes double this amount. About 80% of the salt in our diet comes from packaged foods, not from salt we add to our foods.

Action: Use herbs and spices to flavour your food instead of adding salt. Include more fruits and vegetables in your diet and choose ‘no added salt’ or ‘salt reduced’ products where you can. It also helps to cut back on processed and packaged foods.

4. Excessive alcohol consumption

Long-term and excessive consumption of alcohol can lead to high blood pressure. It’s recommended that men and women drink no more than two standard drinks a day, and no more than four standard drinks on a single occasion.

Action: Aim to stay within the national guidelines for alcohol consumption and become familiar with what constitutes a “standard drink”. If you’re currently over the recommended daily guidelines, then develop a plan to progressively moderate your intake until you’re back within the healthy range. If you need some extra help and support, then talk to your local doctor.

5. Weight

Excess weight increases your risk of developing hypertension. The good news is that regular exercise, eating a healthy diet, and reducing alcohol consumption will help in achieving and maintaining a healthy weight, while lowering your risk of high blood pressure.

Action: If you’re carrying some extra kilos, take steps to lose weight by improving your diet and exercising daily. If you have a lot of weight to lose, or you’re not sure how to go about losing weight safely and effectively, talk to your doctor or a dietitian.

What should I do next?

As there are no high blood pressure symptoms, the only way to know if yours is elevated is to have it checked by a doctor.

If you’re in a higher risk category due to age and/or family history, then have your blood pressure checked by your doctor regularly.

If you’ve already been prescribed medication for high blood pressure, then it’s important that you take your medication as prescribed and monitor your blood pressure over time.

You can also put into place the other lifestyle changes to reduce your risk of high blood pressure, which will also reduce your risk of other related health conditions linked to hypertension.

If you have any other concerns about your blood pressure or associated health risks, then discuss these with your local doctor.

How blood pressure is controlled

When the heart contracts, the blood inside the left ventricle is forced out into the aorta and arteries. The blood then enters small vessels with muscular walls, called arterioles. The tone in the muscular walls of the arterioles determines how relaxed or constricted they are. If narrowed, they resist flow. Reduced flow of blood is detected in the brain, the kidneys and elsewhere. Nerve reflexes are stimulated and hormones are then produced. The heart is induced to beat more forcefully so that blood pressure is maintained at a higher level, to overcome the restricted flow through the arterioles. The achievement of good flow (now at high pressure) eases possible problems for function of the brain and kidneys.

These adjustments occur normally. However, in some people the adjustments become fixed and high blood pressure persists. These people have developed hypertension.

How blood pressure is measured

Hypertension can be mild, moderate or severe. Your blood pressure is naturally higher when you are exerting yourself, such as during physical exercise. It is only a concern if your blood pressure is high when you are at rest, because this means your heart is overworked and your arteries have extra stress in their walls.

Blood pressure readings are a combination of two measurements. These are:

• Systolic – is the highest pressure against the arteries as the heart pumps. The normal systolic pressure is usually between 110 and 130mmHg.
• Diastolic – is the pressure against the arteries as the heart relaxes and fills with blood. The normal diastolic pressure is usually between 70 and 80mmHg.

Sphygmomanometer

Blood pressure is measured using an instrument called a sphygmomanometer.

• An inflatable pressure bag is wrapped around the upper arm. The bag is connected to the sphygmomanometer. The operator pumps up the bag with air until the circulation of the arm’s main artery is interrupted.
• The pressure in the bag is then slowly released until it equals the systolic pressure in the artery, indicated by blood once again moving through the vessel. This makes a ‘thumping’ sound. The systolic pressure is indicated on the sphygmomanometer and recorded.
• The blood pressure in the arm’s main artery drops to equal the lowest pressure, which is the diastolic pressure. This is the pressure at which the thumping sound is no longer heard. This figure is also recorded.
• The operator may take numerous readings to get the true picture. This is because many people tend to ‘tense up’ during the procedure and nervous tension may temporarily boost the blood pressure.
• The accuracy of electronic measuring and recording of both systolic and diastolic pressures is replacing manual and auditory blood pressure recording.

Most people with hypertension feel okay

Hypertension usually does not produce any symptoms, because the organs of the body can resist high blood pressure for a long time. That’s why it’s important to have regular medical examinations to make sure your blood pressure isn’t creeping up as you grow older.

High blood pressure over a period of time can contribute to many illnesses, including:

• heart attack
• heart failure
• kidney disease
• stroke.

An unhealthy lifestyle can cause hypertension

Some of the factors which can contribute to high blood pressure include:

• hereditary factors
• obesity
• lack of exercise
• a diet high in salt
• heavy drinking
• kidney disease.

The effects of high blood pressure on the arteries are worsened by:

• cigarette smoking
• high levels of saturated fat in the diet
• high blood cholesterol
• diabetes.

Responses to some types of stress may affect both blood pressure and changes in the arteries, but this remains scientifically uncertain.

Some drugs may cause hypertension

Certain drugs can cause hypertension or make controlling hypertension more difficult. Check with your doctor or pharmacist for alternatives. These drugs include:

• the combined contraceptive pill
• non-steroidal anti-inflammatories
• some nasal drops and sprays
• some cough medicines, eye drops and appetite suppressants.

Blood pressure and ageing

With advancing years, the arteries tend to become more rigid (less elastic). This may change a person’s blood pressure pattern, with a higher systolic pressure and a lower diastolic pressure. The higher systolic pressure is important because it can further accelerate the rigidity of the arteries. This state is referred to as ‘isolated systolic hypertension’. Although these changes are due to ageing, this is not a normal state and may need medication to control the systolic pressures.

Making healthier choices

Two out of five people can successfully lower their blood pressure by making adjustments to their lifestyle. For example, a low-fat diet and giving up cigarette smoking will reduce the damaging effects of hypertension on the arteries. Some healthy lifestyle choices include:

• Maintain your weight within the healthy range.
• Eat a high-fibre, low-fat and low-salt diet.
• Give up smoking.
• Limit alcohol consumption.
• Exercise regularly.

See your doctor before you start any new exercise program.

Antihypertensive medications

In most cases, it is necessary to take antihypertensive medication as well. Usually hypertensive medication is introduced at low doses. The dose may be gradually increased if needed. A second or even a third drug may be added to achieve good blood pressure control. Not many people experience unpleasant side effects.

Any drug treatment for hypertension needs to be monitored carefully by your doctor. You should never alter the dose of your hypertension medication or stop taking it without consulting with your doctor. Medications don’t cure the condition and most of the people who need to take antihypertensive drugs will do so for the rest of their lives.

Where to get help

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