High blood pressure: How it can harm your health
What is hypertension?
Blood pressure is the pressure of the blood in the arteries as the heart pumps it around the body.
Blood pressure is recorded as two numbers, such as 120/80. The larger number indicates the pressure in the arteries as the heart squeezes out blood during each beat. It is called the systolic blood pressure. The lower number indicates the pressure as the heart relaxes before the next beat. It is called the diastolic blood pressure.
The following figures for blood pressure can be used as a guide1:
- Normal blood pressure: less than 120/80
- High/Normal: between 120/80 and 140/90 (or up to systolic pressure of 130 if you have chronic kidney disease)
- High: equal to or more than 140/90
- Very high: equal to or more than 180/110
Hypertension for adults is defined as a systolic blood pressure of 140 mmHg or higher or a diastolic blood pressure of 90 mmHg or higher.
Blood pressure can be elevated temporarily when you exert yourself through exercise or even when you are excited. Hypertension is when blood pressure is raised at rest or most of the time.
Why is hypertension important?
Hypertension is:
- often called the 'silent killer' because it usually has no noticeable warning symptoms until other serious problems arise. Many people do not know that they have it.
- a major risk factor for heart disease and heart failure. If the heart has to pump against a higher pressure for a long time (years) it can lead to weakness of the wall of the heart and heart failure.
- a major risk factor for stroke that may be caused by a blocked artery that supplies blood and oxygen to the brain.
- a condition that can damage the eyes and result in kidney disease or kidney failure.
General Statistics
- Hypertension affects almost 3.7 million Australians over the age of 25 and can cause serious and irreversible damage to the body.2
- Due to lack of any apparent symptoms, it usually goes undiagnosed.
What causes high blood pressure?3
Major causes of hypertension include obesity or overweight, alcohol consumption, physical inactivity, dietary salt intake and nutrition patterns that involve a low intake of fruit and vegetables and a high intake of saturated fat.
Stress raises blood pressure transiently but in the long term may have indirect effects by influencing eating, drinking, smoking and physical activity patterns. Tobacco smoking increases the risk of heart attack and stroke threefold in hypertensive individuals.
The taking of some medications can result in raised blood pressure, including non-steroidal anti-inflammatory drugs, oral contraceptives, corticosteroids and some antidepressant medications.
Who is at risk?
Some of the risk factors include:
- Hereditary factors
- Obesity / overweight
- 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
- Some medications
What can I do to lower my blood pressure or prevent high blood pressure?
Visit your GP annually for a general health check. A range of lifestyle changes can help lower your blood pressure.
- Maintain a healthy weight
Being overweight or obese can raise your blood pressure, and losing weight can help lower your blood pressure. Even a modest reduction in weight can lower your blood pressure to some extent. - Be active
Physical activity can help lower blood pressure. The World Health Organisation recommends that adults engage in moderate-level physical activity for at least 30 minutes on most days of the week. - Maintain a healthy diet
Eat plenty of fresh fruit and vegetables, lower salt intake and increase potassium intake. Low saturated fat and cholesterol are part of an overall healthy diet. - Stop smoking and moderate alcohol use
- Prevent and control diabetes
- Medications
Your doctor may prescribe medications and lifestyle changes to bring high blood pressure under control. It is important to take the medications prescribed to you. If you change your lifestyle then your doctor may review the need for medication. - Genetic factors
While it is possible that an increased risk of hypertension in the family is due to lifestyle factors such as poor eating habits and these should be considered for preventing and controlling high blood pressure, the largest contribution to high blood pressure is individual genetic composition.
Where do I go for more information?
You should talk to your GP about your health or blood pressure or call 000 if you experience any chest pain or discomfort. Visit the Heart Foundation website or call 1300 36 27 87.
1, National Heart Foundation of Australia (National Blood Pressure and Vascular Disease Advisory Committee). Guide to management of hypertension 2008. Updated August 2009. Web version. 2009
2, Australian Institute of Health and Welfare
3, Better Health Channel: Blood pressure (high) - hypertension