High Blood Pressure
25/06/2011 23:53
High Blood Pressure
Introduction
Hypertension (high blood pressure) is the most
common reason that patients see their doctors.
This article will provide information about what
high blood pressure is and how it can be
treated. Importantly, it will tell you what you
can do to make your treatment successful.
Hypertension is just the medical term for high
blood pressure. Hypertension does NOT suggest
too much tension or nervousness. Throughout
this article we will use the words hypertension
and high blood pressure interchangeably.
What is Blood Pressure?
What is it?
Blood pressure is the force exerted by the blood
against the walls of arteries. We need some
pressure in our blood vessels to get blood to our
organs and muscles. Normally, each time our
heart beats (about 60-80 times a minute at rest),
it pushes blood out into the larger arteries,
which are the tubes that carry blood from the
heart. The blood then flows into smaller arteries
to various parts of the body, such as the kidney
or the brain, and then returns to the heart
through the veins. The smaller arteries, called
arterioles, can open wide or close.
The beating action of the heart may be
compared to a pump. The arteries may be
compared to the tubing of a hose. The arterioles
are like a nozzle. If the nozzle is kept open,
water will flow freely through the hose, and
little pressure is built up on the walls of the
hose. If, however, the nozzle is clamped down,
pressure is built up on the sides of the hose and
the pump must work harder. In the same way, if
the small blood vessels remain open as the heart
beats, blood pressure in the arteries remains
fairly low or normal. If they narrow, higher
blood pressure results.
Blood pressure can vary widely. It can rise
when you are excited or nervous or while you
exercise. The blood pressure is high during the
day and decreases during sleep. Blood pressure
may vary within the course of a day by as much
as 20-30 points in someone with “normal” blood
pressure and even more in someone with
untreated hypertension. Therefore, a single
reading should not be used to make a diagnosis
of high blood pressure.
What is Measured?
Blood pressure is recorded in two numbers as
millimeters of mercury (mm Hg). For example,
120 mm Hg systolic (pumping pressure) and 80
mm Hg diastolic (resting pressure). The
measurement above would be spoken of as “120
over 80,” with the systolic (higher) number
always given first, followed by the diastolic
number.
What Is Normal Blood Pressure?
The normal blood pressure may be as low as
70/50 mm Hg in infants, or as high as 135/85
mm Hg in adults. “Normal” blood pressure for
people under 18 is below 120/80 mm Hg. Over
the age of 18, a reading up to 130-135/80-85 mm
Hg is considered within the normal range. A
diastolic reading between 85-90 mm Hg is
considered “high-normal.” A systolic upper
number) reading of 135-139 mm Hg is also
considered “high-normal.” If an adult's blood
pressure is consistently 140/90 mm Hg or higher, he
or she has high blood pressure or hypertension. The
higher the pressure, the greater the risk.
What About Low Blood Pressure?
People used to believe that low blood pressure
(e.g., about 110/70 mm Hg or below, in an adult)
was dangerous. Except in rare cases, this is not
true. In some cases, people with low blood
pressure may tire easily or faint when standing
in a hot room, but in most cases they have no
symptoms.
Myths and Facts about High
Blood Pressure
MYTH: Hypertension means that a person is
tense or anxious. FALSE
FACT: Hypertension means high blood pressure.
You do not have to be nervous, tense, or jumpy
to develop high blood pressure. Many calm
people suffer from hypertension. Stressful
situations may temporarily elevate blood
pressure but this is not always the case.
MYTH: Loss of excess weight is by itself
enough to cure blood pressure. FALSE
FACT: Obesity (being fat) is associated with
hypertension. More overweight people have
high blood pressure than thinner people. Losing
weight, however, does not guarantee that blood
pressure will return to normal levels, but it will
decrease to some degree. Too often an
overweight person with hypertension is told to
lose weight as his only treatment. Thin people
also can have high blood pressure.
MYTH: Hypertension is a disease of old age.
FALSE
FACT: Most people develop high blood pressure
between 35-50 years of age. Some serious cases
may actually begin at younger ages.
MYTH: Once you have high blood pressure,
and it affects your brain or heart, there is
nothing you can do about it. FALSE
FACT: Just the opposite. Lowering your blood
pressure by proper treatment will often prevent
further brain and heart problems. As blood
pressure is lowered, an enlarged heart becomes
smaller, and therefore, healthier.
MYTH: Hypertension significantly restricts a
person's life. DEFINITELY FALSE
FACT: A person with high blood pressure
should and can lead a normal life, if they are
treated.
MYTH: Medicines that lower blood make
people cause sexual problems. FALSE
FACT: Fewer than 10% of people experience
annoying side effects, which may include sexual
problems. Changing medication or doses of
medication can minimize these effects.
MYTH: Herbal substances and plants, such as
garlic, are effective in lowering blood
pressure. FALSE
FACT: Careful studies have not proven this.
What Causes Hypertension?
In more than 90% of cases we do not know what
causes hypertension! However, there are some
theories. For some reason, in certain people the
small blood vessels at the end of the arteries
seem to contract more forcefully than in other
people. This causes an increase in pressure
within the arteries. This may be due to an
increase in certain nerve impulses with release
of too many blood vessel constricting
substances. In some other people, the kidneys
are unable to wash out enough salt (sodium). As
sodium and fluid build up in the body, the heart
must pump an increasing amount of blood with
each beat. This also increases the blood
pressure. It is not known why these things begin
to happen. Hypertension can be treated even if
it is not known what causes it.
Does Heredity Affect Blood
Pressure?
Children with one parent with high blood
pressure have a greater chance of developing
the disease than those with no high blood
pressure in the family. When both parents have
high blood pressure, the odds are greater still.
This does not mean, however, that all children of
parents with high blood pressure will develop it.
Dietary Factors That May Affect
Blood Pressure
Salt. Eating extra amounts of salt may cause
trouble in some people. There are people who
are 'Salt Sensitive' and others who can eat lots of
salt and not notice a change in blood pressure.
In some people with a family history of
hypertension, a high salt diet starting at infancy
may increase the risk of developing high blood
pressure at a later age. Infants and young
children from these families should be
encouraged to go on a low salt diet at as early
an age as possible.
Fatty foods-Cholesterol. Animal fats tend to
raise our blood cholesterol levels. (An elevated
cholesterol level is, in addition to high blood
pressure, is a major risk factor for heart disease.)
People with hypertension should be careful to
keep their cholesterol levels under control.
What are the Effects of High
Blood Pressure?
Enlarged heart
The heart muscle enlarges if it has to work
harder to push blood out into the body. As the
heart muscle stretches too much or gets too
thick, the heart is no longer able to function
properly. Blood is not pumped forward into the
rest of the body. Some of it backs up in the
lungs. The heart fails.
When the blood pressure is lowered, the heart
does not have to pump as hard each time it
beats. After blood pressure has returned to
normal for a year or two, there is a good chance
that the heart muscle will return toward its
normal size. Heart failure is rare in people whose
blood pressure has been controlled.
Stroke
As blood pressure increases, damage occurs to
the lining of the blood vessels in the brain
forming little blisters called aneurysms. These
aneurysms may rupture suddenly. This causes a
“stroke,” with bleeding i nto the brain and
weakness on one side of the body or a loss of
speech.
Failure of the kidneys to function properly
In the kidney, continued high blood pressure
may cause narrowing and thickening of the
arteries. This reduces the amount of fluid that
the kidney can filter out into the urine building
up waste products in the body. The result can
be kidney failure with 'uremia'. Some uremic
patients may need regular dialysis or undergo
kidney transplants. Many patients on dialysis
programs start out with “sli ghtly elevated blood
pressure” which was not treated effectively.
Early treatment of hypertension will often delay
further damage to the kidney.
Atherosclerosis (Hardening of the arteries)
If blood pressure is not controlled, some of the
fat that normally circulates in our body is
pushed more rapidly into the walls of the
damaged arteries. Plaques (collections of fatty
material) build up in the arteries, like rust on the
inside of a pipe. This condition is called
atherosclerosis or “hardening of the arterie s.”
The higher the blood pressure and the more the
fat (cholesterol) in the bloodstream, the faster
the process. People with untreated high blood
pressure get atherosclerosis at an earlier age.
Heart attack
If the arteries that supply blood to the heart
itself, the “coronary arteries,” become clogged
with fatty material, the blood flow to portions of
heart is reduced. When a vessel is completely
closed, there is a stoppage of blood to that part
of the heart. Portions of that heart muscle are
damaged and a “ heart attack” occurs.
What You Can Do to Reduce the
Complications?
Lose weight
Lose weight if you are overweight. Even small
amounts of weight loss may lower blood
pressure in some people. Losing weight is
probably the single most important non-drug
treatment for high blood pressure.
Watch your salt and fat intake.
Reduce your intake of salty foods and high
cholesterol, high fat foods. Eat balanced meals,
with fruits, vegetables, grains. Weight reduction
and salt restriction may eliminate the need for
specific medication in about 20%-25% of
individuals with less severe degrees of
hypertension, especially in the elderly.
Stop Smoking
Smoking injures blood vessel walls and speeds
up hardening of the arteries. Smoking is a major
risk factor for a heart attack. The smoke itself
causes much damage to blood vessels.
The risk of a heart attack in a person who once
smoked but who has stopped is almost the same
as it is for a person who has never smoked.
Exercise Is Good For You
Go ahead! Do whatever you like to do, but do it
at least 3 or 4 times a week for at least 30-40
minutes, if possible.
Exercise alone may help lower blood pressure in
some people with hypertension. Dynamic or
motion exercises are much better for you than
exercises such as weight lifting. These may help
you develop bigger muscles, but they may not
help you live longer.
Lessening Of Tension
Do things that relax you (other than taking a
tranquilizer). Read. Take up a hobby. Take long
walks. Such activities help to decrease the levels
of adrenaline in the blood and allow the blood
vessels to open up lowering the blood pressure
temporarily. But do not depend solely on relaxation
techniques or vacations to lower your blood pressure.
Drinking and High Blood Pressure
Limit daily alcohol intake to one drink of 80
proof liquor, or 1-2 glasses of beer or 2 glasses of
wine a day. Because women are smaller than
men, one half of the above amount is
appropriate for women. Pregnant women
should not drink alcohol.
All of the above strategies good for you. But,
except in some less severe cases, these may not
by themselves lower blood pressure over time.
In most cases, you must use medications and
usually continue to take them indefinitely.
Facts to Remember
1. High blood pressure may not cause
symptoms. Usually the only way to find out is
to have your blood pressure measured.
2. Tests to evaluate elevated blood pressure are
simple, and hospitalization is rarely necessary.
When blood pressure is under control, doctor
visits need not be frequent (twice a month).
3. The outlook for people with high blood
pressure is excellent. They can look forward to a
long life, free of many of the fears that used to
accompany this diagnosis, as long as they
continue treatment.
4. Being heavy or obese may go along with
having high blood pressure, but losing weight
alone may not control blood pressure in many
people. Losing weight if you are heavy is a good
idea for many other reasons, even if it does not
completely control your blood pressure.
5. You should stop smoking to prevent heart
disease. But stopping smoking by itself will not
lower blood pressure.
6. If you are very anxious, relaxing may help to
lower blood pressure in some less severe cases,
but these treatments will not work in the
majority of patients.
7. A low salt diet may help to lower blood
pressure in some people with less severe
hypertension. A modified low salt and high
potassium diet, however, should be followed in
all cases.
8. Although side effects or annoying symptoms
may occur with some blood pressure lowering
drugs, these usually can be eliminated by
changing doses or switching to another drug.
9. Above all, remember that being on treatment
does not mean that your blood pressure is
controlled. Normal blood pressure cannot be
achieved in everyone, but about 80%-85% of
people with high blood pressure can be
successfully treated regardless of the severity of
their disease.