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How Is High Blood Pressure Diagnosed?

How Is High Blood Pressure Diagnosed

According to some of the older medical text books, and the many popular magazines that claim to make the public more health conscious, high blood pressure always causes headaches, nose bleeds, spots in front of the eyes and a pounding in the head. It is also alleged to make people tired. What is striking in clinical practice is just how unusual these symptoms are, with the exception of tiredness.

It seems that virtually everybody is tired; this is probably a reflection of the fact that in the United Kingdom we work longer hours than most of our European counterparts.

Tiredness is not a specific symptom of high blood pressure but, of course, if you go to your GP complaining of tiredness and you leave the surgery without having had your blood pressure taken, and then I am afraid that your GP is failing in his or her duty to you.

The fact is that the vast majority of people with high blood pressure do not have any symptoms at all, and hypertension may first come to light completely by accident.

Many people going to their GPs complaining of indigestion or a skin rash, for example, will hopefully have their blood pressure taken, which can start the ball rolling. Other people may attend a medical for life insurance or for pre-employment purposes, or even go to one of the many Well Man or Well Woman clinics which are now available.

Sometimes people check their blood pressure at the local chemist’s shop and find it is high. I saw a patient recently who, while visiting his in-laws, had a go on his father-in-law’s new blood pressure machine and found that his blood pressure reading came out as elevated.

These people who have high blood pressure picked up totally by accident should regard themselves as extremely fortunate. Those less lucky may have hypertension diagnosed only after the occurrence of a complication, for example a heart attack, a major or minor stroke, or a cardiac rhythm disturbance.

Sadly, even today hypertension is severely under diagnosed. Doctors in the United States and the United Kingdom have coined the phrase ‘the rule of halves’. This means that in ordinary medical practice only half of all patients with high blood pressure will be correctly diagnosed, and only half of those will receive anti-hypertensive treatment.

Of these, only half of those will have their blood pressure well controlled. Thus, only about 12.5 per cent, or one patient in eight with high blood pressure, receives the correct treatment.

It is not just hypertension that is neglected in this way. Similar studies have shown that unless the medical profession makes a huge effort, we are not as good as we should be at identifying people with elevated cholesterol levels.

A study from the United States showed that only half of the patients who underwent heart operations had had their cholesterol levels measured, and only a small percentage of those received appropriate cholesterol lowering drugs.

Treating high blood pressure saves lives, although it is always difficult to know precisely how many lives could be saved if high blood pressure were treated with appropriate rigour. It is estimated that about 300 people in the United Kingdom die from the complications of high blood pressure every six weeks. Is it acceptable for 300 patients with hypertension to die unnecessarily every six weeks?

Individuals concerned with trying to raise awareness of health issues in the general public have quite rightly pointed out the importance of self-examination for breast lumps, the importance of regular cervical smears, and have tried quite correctly to raise the awareness of testicular and prostate cancer in males. Cancer is a dramatic illness that can kill people quickly, and it captures the public imagination.

Hypertension, unfortunately, is a poor relation grabbing less interest from politicians, and it is not a particularly sexy subject for the health pages of our newspapers. This really is a tragedy.

There are so many people walking around with mild to moderate elevations in blood pressure whose prospect of good health in the future could be greatly enhanced by having their blood pressure treated and avoiding the often catastrophic complications.

I described earlier how doctors make the measurements of systolic and diastolic blood pressure. Although many experts recommend that ideally the patient should be seated, in hospitals it is often done with the patient lying down on a couch.

It is a good idea for the blood pressure be measured at least twice, especially on initial consultations when the person may be unfamiliar with the doctor and with the discomfort of having the cuff pumped up around the arm.

Some consideration must also be given to whether they have just dashed into the surgery with a red face, huffing and puffing, or whether the patient has been seated relaxed in the waiting room for a while. It is generally recommended that the second of the two readings is taken as the more accurate.

Patients may find that there is a discrepancy in the readings obtained at their GP’s surgery compared with readings obtained by a nurse in the Occupational Health Department at work or by a consultant or other hospital doctor.

These differences may reflect the levels of comfort or anxiety of the patient, but unfortunately, some of the errors may be due to the fact that not everybody is trained in how to blood pressure by experienced doctors, while others may have learned in a more academic environment, at medical school, and have not had training continued at a later date.

Another cause for the discrepancy is the use of automatic electronic machines which print out numbers in bright red digits and which involve very little input from the physician or nurse taking the blood pressure!

It is wise to maintain a healthy scepticism about the accuracy of these machines. Please remember that just because a machine prints out a number in bright red digits it does not mean it is accurate; there are some machines that are reliable, and which have been tested and found to be accurate, but this cannot be said for all of them. If you have a machine, it is a good idea to check its accuracy against a standard traditional mercury manometer.

If your GP thinks your blood pressure is high, he or she may well shine a light into your eyes – this is to look at the blood vessels in the retina at the back of your eyes. Long-standing high blood pressure can cause changes in the arteries and veins in the retina; the presence of such changes might give your GP an idea of whether you have had raised blood pressure for a long time.

Often, because of the worry about committing patients to treatment on the basis of one or two readings in a doctor’s surgery, many doctors are now employing a 24-hour ambulatory blood pressure monitor.

This is an intrusive device, as many people who have had one fitted can testify. Essentially, it means wearing a blood pressure cuff attached to a machine that pumps the cuff up automatically several times during the day and night. This checks what your blood pressure is doing in your own environment, rather than in the artificial surroundings of a doctor’s surgery.

Although some blood pressure experts are sceptical about the use of a 24- hour blood pressure monitor, my own view is that it is a very useful clinical tool. It allows doctors to weed out patients who have ‘white coat hypertension’.

But even if the readings are consistently abnormal, they may be less stratospheric than the readings obtained in the doctor’s surgery. This can guide the doctor towards starting treatment with gentler medication and at lower doses than might have been the case if the doctor relied only on the measurement obtained in the surgery.

Your doctor can also see from a blood pressure monitor whether the readings go up during particularly stressful times of the day – it is sometimes possible to tailor specific drug therapy depending on what the monitor shows.

Surveys have shown that not everybody obeys the exact rules about the appearance and disappearance of the pulse sounds. This probably reflects the fact that some people are taught to measure If after reading so far you are curious about why the medical profession is (or at least should be) so obsessed with high blood pressure.

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