by Carl Marshall

Created on: June 21, 2009   Last Updated: November 17, 2011

What is the significance of high blood pressure?

Prospective scientific studies have consistently shown a linear relationship between the height of blood pressure and the development of cardiovascular disease. A person with high blood pressure, also known as hypertension, is twice as likely to suffer a heart attack or stroke. This is because too much pressure strains the heart and arteries.

Hypertension is harmful to the kidneys, the little arteries which interface with the tiny filtering units have too much force against them. Research has shown a strong link to renal cell carcinoma, which is the most common form of kidney cancer.

There is also an increased risk of eye problems such as hypertensive retinopathy, where the high pressure causes the retina to be damaged.

What do the numbers mean?

Two numbers are measured. The top number, known as the systolic number, is the pressure against the arteries when the heart beats. The bottom number, known as the diastolic number, is the force in the arteries when the heart is relaxed.

Normal blood pressure for an adult is 120/80. A diagnosis for hypertension would be made when the systolic number is over 140, and the diastolic number is over 90. It is important not to place too much importance on just one reading. It should be established that your blood pressure is consistently high. Almost everyone will have a high reading sometimes. Indeed, sometimes people register artificially high readings because they are nervous with their doctor. This is known as "white coat hypertension". It is your average reading which is important.

How common is it?

It is estimated that one in three adults has hypertension. Of those who have it, about a third don't realise they have it, due to a lack of symptoms.

Risk factors

There are factors which definitely increase the risk of hypertension. These include smoking, obesity, too much salt, excessive alcohol consumption, sedentary lifestyle and stress. There are also hereditary factors. For example, it has been found black people are at a higher risk than whites.

In terms of diet, an important aspect is the "sodium-potassium ratio". Essentially we should all consume about twice as much potassium than sodium from our diets. We should all try to limit the sodium in our diets, by reducing salt intake. Too much of what people eat is processed food, which contains a lot of sodium. Cutting this out can be beneficial.

Potassium intake can be increased by eating more fruits and vegetables. Aim for at least five portions a day. The DASH diet has been proved to be successful in helping to lower hypertension, and also to help prevent it occurring. It enables the correct sodium-potassium ratio to be achieved. Essentially, it involves eating at least 8 portions of fruit and vegetables each day, along with keeping saturated fat to a minimum.

Smoking should be stopped, even if it means nicotine patches. Alcohol should only be consumed in moderation. Research suggests yoga may be beneficial.

Prescription medication

There are different kinds of medication available to bring blood pressure down to normal. It must be stressed though, that it is better to try to lower it naturally. Research has shown a person on medication, with a reading of 120/80, does not have as low a risk of developing cardiovascular disease, as someone with the same reading who isn't on medication.

Many different hypertension medications exist.  These include ACE inhibitors, angiotensin receptor blockers, beta blockers and calcium channel blockers.  It is not uncommon for two different medications to be prescribed to the patient.

References:

www.nhs.uk

www.bupa.co.uk

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