A person's blood pressure changes
depending on how hard the heart is working. During exercise, for
example, the heart can pump up to three times as fast as during
periods of rest. Two numbers make up a blood pressure reading,
such as 110 over 70. They refer to the pressure within the
arteries during the two phases of heart cycle. Blood pressure is
expressed in numbers equivalent to the pressure exerted by a mercury
column of varying height. The first number or higher number is
called the systolic pressure, designates the pressure during the
period when the heart actually contracts (systole) and thus exerts
maximum force on the walls of arteries at a temporarily increased
pressure during a heartbeat. The second or lower number, called
the diastolic pressure, designates the lower pressure in your arteries
which is present during the longer resting phase (diastole) or relaxed
momentarily between the heart's contractions and fills with blood.
The prefix "hyper" means, in this case, "higher than normal" and has
nothing to do with personality type. Second, the term "malignant
hypertension" refers to blood pressure elevation that is unusually
severe and has nothing to do with cancer.
The more difficult issue is at what
level of systolic or diastolic pressure is high enough to be called
hypertension and to warrant treatment designed to prevent long-term
complications such as heart disease, strokes, and kidney failure.
The following guidelines are provided to verify average diastolic
All adults with average diastolic
pressure greater than 120 should be immediately evaluated and treated.
Those in the range of 105-119 should be
Those in the range of 90-104 should be
individualized for treatment.
Systolic pressure is often elevated by
"hardening" of the arteries as a part of the aging process.
Elevation of systolic pressure alone can also be caused by other
diseases, such as an overactive thyroid gland. Diastolic
elevations, on the other hand, consistently mean hypertension in its
traditional sense. The longer high blood pressure goes
undiagnosed and untreated, the worse the outlook because the heart is
forced to work harder than normal. Imagine blood pressure as a
weight or load that the heart muscle must lift. Like any muscle,
your heart gets larger with constant heavy lifting. Eventually
the heart will no longer be able to cope with the heavy load and its
pumping efficiency decreases. When this happens, the heart
muscle may weaken and heart failure may develop. By accelerating
the development of atherosclerosis (thickening of the arteries), high
blood pressure increases the chances of a stroke or heart attack.
The diagnosis of hypertension should be
reserved for a pattern of consistently elevated blood pressure as
determined by blood pressure readings and it is essential to take
careful measurements by the same person using the same equipment under
relaxed conditions. A person must avoid smoking or taking caffeine
(coffee, tea, cola) for at least half an hour before and be seated for
at least five minutes before measurement/reading is taken. Two
readings should be taken and averaged. In ultimately deciding
whether a given level of pressure deserves treatment, many physicians
will also consider the presence of other factors that tend to increase
the risk of complications, such as, smoking, diabetes, elevated
cholesterol levels and a family history of the complications of
hypertension. There is good reason for being cautious in
labeling someone as hypertensive, because this diagnosis usually leads
to a recommendation for extended if not lifelong treatment, as well as
to increased insurance premiums.
There are also secondary hypertension
cases such as an adrenal gland tumor or a narrowed artery leading to a
kidney. In these instances, surgical correction can replace the
lifelong drug therapy required in most cases of primary hypertension.
The dilemma arises in deciding which persons with accurately diagnosed
hypertension should be subjected to further diagnostic tests for
secondary hypertension. The initial evaluation of all persons
with newly diagnosed hypertension should include, in the opinion of
most experts, a complete blood count, urinalysis, blood levels for
urea nitrogen and/or creatinine (an indirect measure of kidney
function), potassium, glucose and cholesterol and an electrocardiogram
or echocardiogram may also show evidence of thickening of the heart
muscle. These simple tests provide a baseline evaluation of the
individual's heart, kidney and "risks" status, but they do not really
check out the possible causes of secondary hypertension.
Additional studies looking for such causes are usually reserved for
those with the onset of hypertension before age 35 and those with a
rapid onset of hypertension and no family history of the disease.
Its also for those who have failed to respond to initial medical
treatment and with usually severe hypertension. Additional
studies are also done on those with symptoms suggesting an adrenal
tumor. However, the majority of patients with moderate and
uncomplicated hypertension can be treated without costly and
potentially risky testing.
Many times, a treadmill or stress test
is also requested by the doctor. In short, the diagnosis and
treatment of mild hypertension is a tricky business that requires
thoughtful consideration of many factors other than just the numbers.
The very uncertainty about criteria for diagnosis and treatment
carries implications for screening policy. Persons should not
conclude that they have hypertension on the basis of a single blood
pressure reading taken on a drug-store machine or at a street-corner
booth. While such screening programs may be valuable in alerting
someone to the possibility of hypertension, the diagnosis must be
confirmed under the conditions described earlier. This means a
visit one's physician which is an important step toward getting a
Also, it it neither necessary nor
advisable to purchase home equipment for the purpose of "discovering"
high blood pressure though such devices can be extremely useful in
monitoring the progress of treatment. Indeed, we have enough to
worry about without getting our blood pressure checked all the time
because of the possibility that "it might be up". Better to rely
on periodic opportunities to have one's pressure checked by persons
trained to do so.