US Pharm. 2014;39(2):29-30.
Measurement of Force of Arterial Blood Flow
Blood pressure is the term used to describe the force of blood
as it is pumped through the arteries with each heartbeat. A blood
pressure reading consists of two numbers, with the pressure measured in
millimeters of mercury (mmHg). A normal blood pressure reading is less
than 120/80 mmHg, or “120 over 80.” The systolic pressure (top number) is the pressure of the blood in the arteries when the heart beats (pumps blood). The diastolic pressure (bottom number) is the pressure of the blood in the arteries when the heart is resting (between heartbeats).
Readings Can Detect Abnormal Blood Pressure in the Absence of Symptoms
Blood pressure readings can be taken manually or with an automatic
monitoring device. A cuff attached to a gauge is placed above the elbow
of one arm and inflated with a hand pump (or, if a monitor is used, the
cuff inflates automatically). The inflated cuff stops the flow of blood
through the artery in the arm so that a pulse can be clearly heard. The
cuff is then slowly deflated, and a stethoscope (not needed with an
automatic device) is used to listen to the blood flowing through the
artery. When the thumping of blood is heard, the systolic pressure is
noted on the gauge. When the thumping stops, the diastolic pressure is
Importance of Blood Pressure Readings
Blood pressure readings can reveal abnormal pressure in a person
without symptoms, as well as help monitor blood pressure control during
treatment. There are four categories of blood pressure measurements:
normal, prehypertension, stage 1 hypertension, and stage 2 hypertension.
Low blood pressure is usually not serious, but high blood pressure
(hypertension) negatively affects one’s overall health. High blood
pressure puts a strain on the heart, arteries, and kidneys. If left
untreated, it can eventually result in heart attack, stroke, coronary
artery disease, heart failure, or kidney damage.
An estimated 1 in 3 adults in the United States has high blood
pressure. Many people with high blood pressure are unaware of it because
they have no symptoms. It is important to have a blood pressure reading
done at least every 2 years after age 18. Most people have their blood
pressure checked during an annual physical or at a community health fair
or clinic. If one reading is high, pressure measurement should be
repeated several times before a diagnosis of hypertension is made.
Anxiety, caffeine, cigarettes, and some medications can raise blood
pressure temporarily. Some people have higher readings in a doctor’s
office because of nervousness; others have higher readings at home. A
person who has repeatedly high blood pressure readings should be
monitored frequently both in the doctor’s office and at home, and
hypertension treatment should be initiated if the pressure remains high
during more than two office visits.
Methods of Lowering Blood Pressure
Blood pressure can be lowered through lifestyle changes and/or
medications. Weight loss, regular exercise, a low-salt diet, and stress
relief are all proven ways to lower blood pressure. If changes in
lifestyle are not effective, there are medications (antihypertensives)
that can safely lower blood pressure.
People with normal blood pressure should maintain or adopt a healthy
lifestyle to avoid developing high blood pressure in the future.
Individuals with prehypertension should start with lifestyle changes to
reach their blood pressure goal. People with stage 1 hypertension should
make the appropriate lifestyle changes to reach their blood pressure
goal within 6 months, but they may need a prescribed medication if
lifestyle changes are not effective. Stage 2 hypertension is usually
controlled by adopting a healthy lifestyle and using of one or more
antihypertensive medications. Anyone with high blood pressure should
take the prescribed medication exactly as directed.
If you have questions about blood pressure readings, blood pressure
control, drugs that cause high blood pressure, or prescription
antihypertensive drugs, your pharmacist can help.