H I G H  B L O O D  P R E S S U R E

The heart pumps blood containing oxygen and other nutrients through the arteries to the rest of the body. Blood "pressure" is the force exerted on the arteries by the blood passing through them. It is determined by how much resistance there is in the arteries, and is not a measure of how "strong" the heart muscle is.

High blood pressure, or "hypertension", is a very common disorder. It is associated with an increased risk of coronary artery disease, stroke, heart attack, kidney failure, and death. Despite this, it has no symptoms in its early stages. Your blood pressure must be measured to know whether it is high.

The medical community’s knowledge of high blood pressure is great, but far from perfect. However, the biggest problem with treatment of high blood pressure is not a lack of knowledge, but a lack of the application of our current knowledge. Follow the advice below, and you’ll be able to gain control of an important part of your healthcare.

Take your own blood pressure

The pressure exerted on the arteries when the heart is beating is called the "systolic" blood pressure. This is the number at which sounds are first heard through the stethoscope.

The pressure present in the arteries when the heart is not pumping is termed the "diastolic" blood pressure. It is the pressure when sounds are last heard with the stethoscope.

The blood pressure is expressed as the systolic pressure "over" the diastolic pressure. Blood pressure increases as we age, but the number generally regarded as "normal" is 120/80.

What does High Blood Pressure do to the body?

High blood pressure affects the blood vessels, causing them to clog or become weak. It is therefore one of the important factors causing:

What causes high blood pressure?

The majority of times, there is no clear cause which can be identified. In a few patients (approximately 2%), high blood pressure may be traced to other "secondary causes" (see next section).

The actual mechanisms which explain why the blood pressure is high has to do mainly with the constriction of the small arterioles which are in all of the tissues of the body. When these are even slightly smaller than normal, the overall effect is that of a marked decrease in the volume that blood can flow in. Imagine a hose: You put a narrow nozzle at the end – the pressure really goes up in the hose, doesn’t it!

High blood pressure is more common:

High blood pressure has its roots in many cases simply with the genes we received from our parents. High blood pressure is far more common in families where other members have this condition. This does not mean that you must have a history of high blood pressure in your family to have it yourself. It is very interesting to note that while the incidence of high blood pressure is low in Japan, it is higher in Japanese who migrate to America, underscoring the idea that there are things that we do culturally that will affect the incidence of high blood pressure. These include:

There are many other factors which have been felt to be related to high blood pressure. While these are interesting topics of debate and scientific curiosity, they are not nearly as important as the factors listed above.

Secondary causes of high blood pressure

The "average" or "run of the mill" case of high blood pressure is caused by the genes that are inherited with very important contributions from lifestyle. This is "Primary" Hypertension, and is discussed in the section above. About 2% of the time, there are specific abnormalities which are an identifiable reason for high blood pressure in some people. Some of these causes include"

Again, it is worth remembering that these are all pretty uncommon conditions. Their presence may be suggested by an early age of onset of hypertension, or a sudden worsening, or difficulty in treatment. Still, most cases even in these categories will be due to "plain old primary" hypertension. Investigations to "rule out" these conditions may include a careful history, particularly for some of the kidney diseases. Various features of the physical examination, including bruits (particular noises heard with the stethoscope when blood rushes through narrowed arteries) in the case of Renal Artery Stenosis, or substantial differences in the blood pressure in the arms and legs (in the case of coarctation) can be helpful. Measuring certain chemicals in the blood or urine are important in the abnormal conditions of the adrenal gland. Specialized imaging techniques, such as ultrasound, nuclear medicine studies, CT scans or MRI's, or arteriograms may be needed to diagnose the disorders.

When and how is high blood pressure treated?

There is debate (when isn't there?) about the level of blood pressure which should be treated. As in so many areas, the debate often obscures the obvious - the higher the level of the blood pressure, the higher the risk of suffering one of its complications.

Likewise, there is tremendous debate about how patients should be treated. Again, don't overlook the obvious in this situation either. People with hypertension should be encouraged to:

Medications may also be required to maintain adequate control. As in any other area of medicine, when to start medications is a decision balancing the risks and benefits of therapy. In patients with high blood pressure, side effects and costs of medications are also factors which weigh heavily on which agent if any is prescribed. For the physician, it is a difficult area due to the fact that patients don't feel bad, yet must be prescribed medicines which can be costly and have side effects which make the patient feel worse than they did prior to treatment.

At what level is blood pressure too high?

First of all, several readings are required to diagnose High Blood Pressure. Blood pressure is generally felt to be abnormally high at a level of 140/90, and some sort of definitive therapy and follow-up should be started at this level. This may involve weight loss, a low salt diet, and a modest exercise program. It should definitely lead to follow-up appointments, and if the pressures remain high, therapy with medications.

My blood pressure is so high, I'm going to have a stroke!

This is really far less common than is feared. In the "old days" before we had so many different and effective medications for high blood pressure, a person's pressure could go very high and stay there . . . or go even higher. Nowadays, it is very uncommon for this to occur. Remember, when people exercise, their blood pressure typically goes up to the 160-210 mmHg range -- your arteries were meant to take this level. Certainly, levels this high all the time can lead to very substantial problems, but these are generally long-range problems, not something that's going to happen right now.

Can’t you tell when your blood pressure is high?

I would say definitely not. It is not called the "silent killer" for nothing. I have met patients who have really felt they can tell when their pressure is high, and indeed when they have a headache or blurry vision it may be quite high. However, I have yet to meet anyone who is anywhere near as accurate as a blood pressure cuff! There are two dangers to believing you can tell your blood pressure, and I have seen many cases of both:

The only way to know whether you have high blood pressure is to have it taken by a person who knows how (those automatic machines you sit at in the supermarket are not necessarily kept accurate condition!). Even if you’ve previously had normal pressure, you should have it taken at least once a year.

My prescription ran out. Does that mean my blood pressure is cured?

Again, definitely not. Unfortunately, most patients will need to take some sort of medication for the rest of their lives. Fortunately, this will do them a great deal of good. But the medicines don’t "cure" the high blood pressure like antibiotics cure an infection. You have to take the medications continuously for them to work. Call your doctor’s office and get refills!

Will I ever be able to get off of these medications?

In general, patients will need to continue their medications indefinitely. Changes in lifestyle already mentioned may be successful in helping you get off your medications with your doctor’s guidance. My practice has been to treat sustained high blood pressure once it has been documented appropriately, and then back it off if the patient is following those lifestyle changes and the pressure is under good control. The desire to get off meds gives them motivation to lose weight, etc.

Should I get a blood pressure cuff? Which one?

I personally feel that patients with hypertension should have a blood pressure cuff at home. I have found the "finger cuffs" pretty unreliable in general, although some are accurate. Some are easier than others to use by yourself, a less important feature if you have a friend or mate who will do it for you. Regardless of the type of cuff, bring it to your physician’s office so that they can check for its accuracy when you first buy it, and then every year or two (or after it takes a fall).

Why does my blood pressure vary so much?

Many people seem to feel that blood pressure is a constant, like the color of their hair. However, like our pulse rate, blood pressure is designed to vary depending on the circumstances. If a person has a widely varying blood pressures, it is referred to as "labile". The blood pressure to consider in treatment is often somewhere around the average of the readings taken. If a person’s systolic blood pressure is ranging from 100-130 mm mercury, generally no treatment is necessary.

But I can’t have high blood pressure! My blood pressure has always been normal!

This is one of my secret favorites. It is not as amazing when you consider the fact that every case of high blood pressure has to start somewhere!

Exactly when should I take my medication? What should I do if I forget a dose?

This will vary from one medication to another, and from one patient to another. Ask your doctor or pharmacist.

What is "White Coat Syndrome"?

"White coat syndrome" is a situation where patients have high blood pressure in the doctor’s office but nowhere else. The situation is generally not this clear-cut, however, and often the patient has occasional episodes where the blood pressure is high when taken at home, but it is reliably high when taken in the physician’s office. Some patients with sustained high blood pressure will have higher readings in the doctor’s office than at home. It is really not very uncommon. The patient generally does not feel the slightest bit of apprehension when coming to the doctor, or even in the office when the blood pressure is high. The mechanism appears to occur at a subconscious level.

If blood pressure is just very occasionally high, it is not as dangerous as when it remains elevated most of the time. If in fact the blood pressure is noted to be high almost exclusively in the doctor’s office, many physicians will not prescribe any treatment at all. Some studies have suggested however that white coat hypertension may "turn into" sustained high blood pressure. This really makes more sense to me since the same types of stresses occur in everyday life.

There are two main problems or dangers with this condition:

The most prudent course seems to be:

Are there any medications I should avoid?

"Over-the-counter" medications that include decongestants can drive your blood pressure up. These are used in cold/sinus/cough preparations. Pure "antihistamines" without are generally safe, as are several prescription preparations. Tell your pharmacist that you have high blood pressure, and ask which preparations to take, and which to avoid.



©COPY;1997 HeartPoint   Updated July 1997

|  Commentary  |  Food You Will Love  |  HeartPoint Gallery  |  In The News |  Health Tips  |  What's New
|  Information Center  |  Home  |

This site presents material for your information, education and entertainment. We can assume no liability for inaccuracies, errors, or omissions. Above all, material on this site should not take the place of the care you receive from a personal physician. It is simply designed to help in the understanding of the heart and heart disease, and not as a diagnostic or therapeutic aid. You should seek prompt medical care for any specific health issues. Please feel free to browse the site and download material for personal and non-commercial use. You may not however distribute, modify, transmit or reuse any of these materials for public or commercial use. You should assume that all contents of the site are copyrighted. ©COPY;1997 HeartPoint