ABC of Vascular Disease
High blood pressure (hypertension)
1. What is blood pressure?
The blood pressure in the arteries is what drives the blood around the
body. The blood pressure is generated by the pumping action of the heart
and the blood pressure goes up as the heart beats and goes down between the
beats. The blood pressure varies between the higher pressure (called the
systolic pressure) and the lower pressure (called the diastolic pressure).
The body regulates the average blood pressure so that it is kept above a certain
level to ensure that enough blood will flow and below a certain pressure to
prevent damage to the heart and arteries. The blood pressure is affected
by a number of separate factors: the heart, the state of the large arteries and
the size of the small arteries. Your blood pressure changes from
minute to minute depending on what you are doing: it is lowest during sleep and
highest during stressful situation and exercise. These changes are normal and do
not indicate a problem. As you get older your arteries get stiffer and the
systolic pressure tends to increase.
2. What is hypertension?
Hypertension is high blood pressure. Most patients with hypertension have
no obvious cause (essential hypertension). A few have an underlying cause
(secondary hypertension) which if treated will usually also cure the
3. What problems does hypertension cause?
Hypertension causes a number of problems including heart, brain and kidney
damage, and damage to the delicate lining of the arteries. Hypertensive
patients are more likely to development of occlusive and aneurysmal arterial disease and will aggravate other risk factors such as
and diabetes. Hypertensive patients have a
higher risk of strokes and heart attacks.
4. How is hypertension diagnosed?
Simply by measuring the blood pressure using a cuff around the arm and a
stethoscope to listen over the artery. As blood pressure is normally quite
variable is is necessary to have a number of abnormally high readings before
hypertension can be diagnosed with confidence. Some patients feel anxious
when they see a doctor to have their blood pressure measured and this may give
an incorrectly high reading (white coat hypertension). Sometimes it is
necessary to measure the blood pressure repeatedly over a period of time to get
a reliable estimate and this can be done by wearing a portable, automatic blood
pressure machine (ambulatory blood pressure). Other tests may be done to
assess if hypertension has caused damage (e.g electrocardiogram, chest x-ray,
blood test) of if it is secondary to another problem.
5. How is hypertension treated?
In mild cases a change of diet may be all that is required to
bring down the blood pressure (e.g. too much alcohol increases blood pressure).
Daily drugs are required if the hypertension is more severe. Which drug is
used depends on the degree of hypertension and any co-existing medical
problems. There are flour main classes of drug used to treat hypertension:
These different types of treatment are additive so treatment of hypertension
usually starts with low doses of one drug. If the hypertension is
resistant to this treatment the doses are increased and/or different drugs used
together. Patients on treatment for hypertension should have their blood
pressure checked to ensure the treatment is effective. Patients should not alter
the dose of their anti-hypertensive drugs without advice from their doctor.
6. Is there a cure for hypertension?
Unfortunately not, unless the hypertension is secondary to another problem.
7. How effective is the treatment?
Large clinical trials have shown that patients with hypertension are at
lower risk of complications such as strokes if the high blood pressure is
controlled. Treatment of hyperlipidaemia does not guarantee complete
immunity to complications, instead it reduces the likelihood of having a complication.