What is high blood pressure?
It causes the heart to work harder than normal putting both the heart and arteries at greater risk of damage. High blood pressure, or hypertension, increases the risk of heart attacks, strokes, kidney failure, damage to the eyes, congestive heart failure and atherosclerosis.
Hypertension exists where the pressure at which blood is pushing against blood vessel walls is consistently above average. Untreated high blood pressure can cause the heart to become abnormally large and less efficient (ventricular hypertrophy) causing heart failure and increased risk of heart attack.
Although high blood pressure can cause headaches, dizziness and problems with vision, the majority of people suffer no symptoms at all. As a result many people with hypertension remain undiagnosed because they have no symptoms to motivate them to see a doctor or get their blood pressure checked.
Causes and risk factors
In over 90 per cent of cases, the cause is unknown. In the remaining cases, high blood pressure is a symptom of a recognisable underlying problem such as a kidney abnormality, tumor of the adrenal gland or congenital defect of the aorta (in these cases when the root cause is corrected, blood pressure usually returns to normal). This type of high blood pressure is called secondary hypertension.
If high blood pressure isn't treated and is combined with obesity, smoking, high blood cholesterol levels or diabetes, the risk of heart attack is several times higher.
Treatment and recovery
The only way to find out if you have high blood pressure is to have your blood pressure checked. A doctor or other qualified health professional should check a patient's blood pressure at least once every two years.
It’s measured in millimetres of mercury (mm Hg) and is defined in an adult by the recording of two readings:
• The first is called the systolic pressure and represents the force of the blood as the heart contracts (beats) to pump it around the body. This is the higher of the two readings and records blood pressure at or above 140mm Hg.
• The second, called the diastolic, is the pressure while the heart is relaxed and filling with blood again in preparation for the next contraction or heart beat. This value is lower than the systolic pressure and records blood pressure at or above 90mm Hg.
When high blood pressure is first diagnosed, tests may be done for an underlying cause (i.e. secondary hypertension) especially if the person is young or has very high blood pressure. If an underlying cause is found it should be treated.
There's no cure as such for essential hypertension, but following a healthy lifestyle can be enough to bring blood pressure down to a normal level. This is one reason why drug treatment may not be offered for healthy individuals with only mild hypertension (above 140/90 mmHg but below 160/100 mmHg).
All medicines can have side effects and sometimes it’s necessary to try different drugs if initial treatments cause problems.