What is hypertension? (high blood pressure)
Hypertension, or high blood pressure, is a common and serious condition. But a diagnosis of hypertension is definitely not the end of the world. When it is well-controlled, the risk of suffering its long-term consequences is greatly reduced.
What is “blood pressure” and “high blood pressure”?
The term “blood pressure” refers to the force of blood pushing against artery walls as it courses through the body due to the pump action of the heart. Blood pressure is essential to life – it keeps blood flowing through your body, providing oxygen and energy to your organs.
Normal blood pressure fluctuations, experienced by all people when they exercise, are startled, excited or in pain, are not problematic, as long as the pressure returns rapidly to a normal baseline. It is the sustained increase in blood pressure that causes havoc.
Just as too much air pressure can damage a tyre, so high blood pressure can damage your blood vessels, particularly the arteries, and vital organs, such as your heart, brain and kidneys.
High blood pressure can be compared to taking a garden hose and reducing the opening at the nozzle. Pressure in a hose can of course also be raised by increasing the amount of water flowing from the tap. Similarly, the amount of circulating blood, and the strength of the heart muscle contractions, can also influence your blood pressure. Blood pressure rises when you are active and falls when you are inactive.
How blood pressure is measured
The technique of using a blood pressure cuff placed around the upper arm, and listening to the sounds of the turbulence in the artery, has been in use for over 100 years.
A blood pressure measurement is made up of two parts: systolic and diastolic. Systolic pressure occurs in arteries during heart contraction (which is called a systole), and diastolic pressure during the period of heart relaxation between beats. This is why a blood pressure measurement is expressed as one figure "over" another, for example 120/80 mmHg. Systolic pressure is obviously always higher than diastolic blood pressure.
How high is high?
A blood pressure reading of 120/80 mmHg or less is optimal, and average blood pressure during the day should not exceed 130/80 mm Hg. Hypertension is diagnosed when blood pressure is consistently above 140/90 mmHg.
Blood pressure of between 130/80 and 140/90 mmHg is considered a high normal blood pressure and it is likely this will progress to hypertension over the next two to five years unless there are dramatic changes towards a healthy lifestyle.
In high-risk patients such as diabetics, blood pressure may be treated with medication even in the high-normal range.
The following table shows normal blood pressure ranges and stages of hypertension. High-normal blood pressure requires more regular monitoring. Stage 1 is less severe than Stage 3.
|Blood pressure||Systolic (mm Hg)||Diastolic (mm Hg)|
|Optimal||120 or less||80 or less|
|Normal||Less than 130||Less than 80|
|High normal||130 -139||80 – 89|
|Stage 1 (Mild)||140 - 159||90 – 99|
|Stage 2 (Moderate)||160 - 179||100 – 109|
|Stage 3 (Severe)||180 or higher||110 or higher|
A diagnosis of hypertension may sound scary, and yes, it can be dangerous if not managed well, but here’s the good news: a person with high blood pressure can lead a long and healthy life if blood pressure is well-controlled.
Why hypertension is called the “silent killer”
Under the heading "Common Hypertension Symptoms", an author of a medical textbook left the entire page blank – he was emphasising the absence of symptoms in most people with hypertension.
The great majority of people with hypertension feel fine and have few symptoms. They only learn of their condition during a routine examination or an examination for some other problem, or when they unexpectedly have a stroke or heart attack.
Hypertension may go undetected for years, while quietly causing damage. This is why all adults, even those feeling “healthy” and who lead a healthy lifestyle, should have their blood pressure measured on a regular basis.
Occasionally, people with high blood pressure report frequent headaches, dizziness, fatigue and pounding of the heart. These symptoms may be related to hypertension.
Extreme cases of hypertension – especially with levels greater than 180/110mmHg – may cause the following profound symptoms:
- Headaches, especially pulsating headaches behind the eyes
- Visual disturbances
- Nausea and vomiting
- Disturbed levels of consciousness such as sleepiness and even seizures.
Who is at risk?
A survey completed in 2010 by the Heart Foundation of Australia found one in three Australians aged 30-65 years had been told by a doctor that they have high blood pressure
High blood pressure tends to run in families. It is more likely to affect men than women and those over 55 years of age. Hypertension is also more likely to affect people who are overweight, inactive, consume a lot of alcohol, smoke and/or eat food high in animal fat and salt. Black and Aboriginal people tend to develop hypertension at an earlier age than other groups.
Diet and exercise are the 2 most effective means of reducing hypertension. But sometimes lifestyle changes alone are not enough. Increasing your intake of omega-3 fatty acids, garlic, cod liver oil and coenzyme Q10 (CoQ10) can naturally reduce hypertension reduction. In severe / dangerous cases, your doctor may need to prescribe medication. In less severe cases, use of aspirin may be advised by your doctor to help provide some relief from hypertension.
Want more info? Read "How to Reduce Your Risk of Hypertension."
Image via Thinkstock