High Blood Pressure (cont.)
How is end-organ damage assessed in the
patient with high blood pressure?
Damage of organs fed by the circulatory system due to uncontrolled hypertension is called end-organ damage. As already mentioned, chronic high blood pressure can lead to an enlarged heart,
kidney failure, brain or neurological damage, and changes in
the retina at the back of the eyes. Examination of the eyes in patients with
severe hypertension may reveal damage; narrowing of the small arteries, small
hemorrhages (leaking of blood) in the retina, and swelling of the eye nerve. From the amount of
damage, the doctor can gauge the severity of the hypertension.
People with high blood pressure have an increased
stiffness, or resistance, in the peripheral arteries throughout the tissues of
the body. This increased resistance causes the heart muscle to work harder to pump
the blood through these blood vessels. The increased workload can put a strain
on the heart, which can lead to heart abnormalities that are usually first seen
as enlarged heart muscle. Enlargement of the heart can be evaluated
by chest x-ray, electrocardiogram, and most accurately by
echocardiography (an
ultrasound examination of the heart). Echocardiography is especially useful in
determining the thickness (enlargement) of the left side (the main pumping side)
of the heart. Heart enlargement may be a forerunner of heart failure,
coronary (heart) artery disease, and
abnormal heart rate or rhythms (cardiac
arrhythmias). Proper treatment of the high blood pressure and its complications
can reverse some of these heart abnormalities.
Blood and urine tests may be helpful in detecting kidney abnormalities in people
with high blood pressure. (Remember that kidney damage can be the cause or the
result of hypertension.) Measuring the serum creatinine in a blood test can
assess how well the kidneys are functioning. An elevated level of
serum creatinine indicates damage to the kidney. In addition, the presence of
protein in the urine (proteinuria) may reflect chronic kidney damage from
hypertension, even if the kidney function (as represented by the blood
creatinine level) is normal. Protein in the urine alone signals the
risk of deterioration in kidney function if the blood pressure is not
controlled. Even small amounts of protein (microalbuminuria) may be a signal of
impending kidney failure and other vascular complications from uncontrolled
hypertension. African American patients with poorly controlled hypertension are at a higher
risk than Caucasians for most end-organ damage and particularly kidney damage.
Uncontrolled hypertension can cause strokes, which can lead to brain or neurological damage. The strokes are usually due to a hemorrhage (leaking blood) or
a blood clot (thrombosis) of the
blood vessels that supply blood to the brain. The patient's symptoms and signs
(findings on physical examination) are evaluated to assess the neurological
damage. A stroke can cause weakness, tingling, or paralysis of the arms or legs
and difficulties with speech or vision. Multiple small strokes can lead to
dementia (impaired intellectual capacity). The best prevention for this
complication of hypertension or, for that matter, for any of the complications,
is control of the blood pressure. Recent studies have also
suggested the angiotensin receptor blocking drugs may offer an additional
protective effect against strokes above and beyond control of blood pressure.
- High blood pressure (hypertension) is designated as
either essential (primary) hypertension or secondary hypertension and is
defined as a consistently elevated blood pressure exceeding 140/90 mm Hg.
- In essential hypertension (95% of people with
hypertension), no specific cause is found, while secondary hypertension (5% of
people with hypertension) is caused by an abnormality somewhere in the body,
such as in the kidney, adrenal gland, or aortic artery.
- Essential hypertension may run in some families and
occurs more often in the African American population, although the genes for essential
hypertension have not yet been identified.
- High salt intake, obesity, lack of regular exercise,
excessive alcohol or coffee intake, and smoking may all adversely affect the
outlook for the health of an individual with hypertension.
- High blood pressure is called "the silent killer"
because it often causes no symptoms for many years, even decades, until it
finally damages certain critical organs.
- Poorly controlled hypertension ultimately can cause
damage to blood vessels in the eye, thickening of the heart muscle and heart
attacks, hardening of the arteries (arteriosclerosis), kidney failure, and
strokes.
- Heightened public awareness and screening of the
population are necessary to detect hypertension early enough so it can be
treated before critical organs are damaged.
- Lifestyle adjustments in diet and exercise and
compliance with medication regimes are important factors in determining the
outcome for people with hypertension.
- Several classes of anti-hypertensive medications are
available, including ACE inhibitors, ARB drugs, beta-blockers, diuretics,
calcium channel blockers, alpha-blockers, and peripheral vasodilators.
- Most anti-hypertensive medications can be used alone
or in combination: some are used only in combination; some are preferred over
others in certain specific medical situations; and some are not to be used
(contraindicated) in other situations.
- The goal of therapy for hypertension is to bring the
blood pressure down to 140/85 in the general population and to even lower
levels in diabetics, African Americans, and people with certain chronic kidney diseases.
- Screening, diagnosing, treating, and controlling hypertension early in
its course can significantly reduce the risk of developing strokes, heart
attacks, or kidney failure.
Previous contributing medical author: Dwight Makoff, MD
Last Editorial Review: 8/6/2008
- ACE Inhibitors - Read about ACE inhibitors like Altace, lisinopril, enalapril, ramparil, Zestril and more. Information includes side effects, drug interactions, and pregnancy safety information.
- Creatinine Blood Test - Learn more about the creatinine blood test, a test that measures kidney function. Abnormal creatinine levels in the blood may indicate kidney disease.
- Congestive Heart Failure - Read about congestive heart failure symptoms like fatigue, abdomen, leg and ankle swelling, shortness of breath, sleeplessness, increased urination, nausea, abdominal pain, and decreased appetite.
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