- Systolic: less than 120 mm Hg
- Diastolic: less than 80 mm Hg
Blood pressure is usually written as systolic/diastolic mm Hg. For example, a reading of
120/80 mm Hg, is said as ”one twenty over eighty.” These measures of arterial pressure are
not static, they change with each heartbeat and during the day. Factors such as age, gender
and race also influence blood pressure values. Pressure also varies with exercise, emotions,
sleep, stress, nutrition, drugs, or disease.
Studies have shown that people whose systolic pressure is around 115 mm Hg rather than
120 mm Hg have fewer health problems. Clinical trials have shown that people who have
arterial pressures at the low end of these ranges have much better long term cardiovascular
health.
Hypertensionwhich is also calledhigh blood pressure,is a condition in which a person’s
blood pressure is always high. Hypertension is said to be present when a person’s systolic
blood pressure is always 140 mm Hg or higher, and/or their diastolic blood pressure is always
90 mm Hg or higher. Having hypertension increases a person’s chance for developing heart
disease, having a stroke, and other serious cardiovascular diseases.
Hypertension often does not have any symptoms, so a person may not know they have
high blood pressure. For this reason hypertension is often called the silent killer. However,
hypertension can be easily diagnosed and is usually treatable. Treatments for hypertension
include diet changes, exercise, and medication.
Atherosclerosis and Other Cardiovascular Diseases
A cardiovascular disease (CVD) is any disease that affects the cardiovascular sys-
tem. But, the term is usually used to describe diseases that are linked to atherosclerosis.
Atherosclerosisis a chronic inflammation of the walls of arteries that causes swelling and a
buildup of material calledplaque.Plaque is made of cell pieces, fatty substances, calcium,
and connective tissue that build up around the area of inflammation. As a plaque grows it
stiffens and narrows the artery, which reduces the flow of blood through the artery, shown
inFigure18.22.
Atherosclerosis
Atherosclerosis normally begins in later childhood, and is usually found in most major arter-
ies. It does not usually have any early symptoms. Causes of atherosclerosis include a high-fat
diet, high cholesterol, smoking, obesity, and diabetes. Atherosclerosis becomes a threat to
health when the plaque buildup interferes with the blood circulation in the heart or the
brain. A blockage in the blood vessels of the heart can cause aheart attack. Blockage of the