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$Unique_ID{BRK03847}
$Pretitle{}
$Title{Hypertension}
$Subject{Hypertension Arterial Hypertension High Blood Pressure Essential
Primary Hypertension Secondary Hypertension Renal Renovascular Hypertension
Systolic Hypertension}
$Volume{}
$Log{}
Copyright (C) 1992 National Organization for Rare Disorders, Inc.
784:
Hypertension
** IMPORTANT **
It is possible that the main title of the article (Hypertension) is not
the name you expected. Please check the SYNONYM listing to find the
alternate names and disorder subdivisions covered by this article.
Synonyms
Arterial Hypertension
High Blood Pressure
Disorder Subdivisions:
Essential (or Primary) Hypertension
Secondary Hypertension
Renal (or Renovascular) Hypertension
Systolic Hypertension
General Discussion
** REMINDER **
The information contained in the Rare Disease Database is provided for
educational purposes only. It should not be used for diagnostic or treatment
purposes. If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.
Hypertension is defined as persistent elevation of blood pressure. Blood
pressure is the amount of pressure placed on the walls of the arteries as
blood is pumped throughout the body. (Generally, normal blood pressure is
considered 120/80, but can be anywhere from 100/60 to 140/90. Blood pressure
is measured by an instrument called a sphygmomanometer.) The systolic blood
pressure is the upper reading which measures pressure when the heart muscle
is contracting. The diastolic blood pressure is the lower reading which
measures pressure when the heart muscle is at rest. Blood pressure varies
depending on age, altitude, activity, posture and from person to person.
When only the systolic blood pressure is high, it is referred to as
systolic hypertension.
Symptoms
Hypertension is ordinarily discovered during a routine examination. There
are usually no outward symptoms. However, when blood pressure is extremely
high, there may be symptoms of headache, heart failure, and/or vision
disturbances.
When hypertension is untreated it can cause damage to the heart, blood
vessels and kidneys. It can also lead to congestive heart failure,
mini-strokes (transient ischemia attacks; TIA), strokes, and kidney failure.
This is why it is important for people with high blood pressure to receive
medical treatment even though they may feel perfectly healthy.
Causes
In over 95% of people who have hypertension there is no discernible cause.
When the cause is unknown, high blood pressure is referred to as essential or
primary hypertension.
In secondary hypertension, the cause is known. Some known causes of
secondary hypertension are kidney diseases (renal or renovascular
hypertension) including kidney failure due to any cause. Endocrine disorders
such as Acromegaly, Hyperthyroidism, Cushing's Syndrome, Congenital Adrenal
Hyperplasia, or Pheochromocytoma can also cause secondary hypertension.
Other causes of hypertension include neurological disorders such as
Encephalitis, Acute Porphyria, Familial Dysautonomia, or Guillain-Barre
Syndrome. (For more information on these disorders, choose "encephalitis,"
"porphyria", "dysautonomia," and "Guillain-Barre" as your search terms in the
Rare Disease Database.)
In some patients, hypertension may be caused by hereditary factors or by
high salt intake (especially in people who inherited the tendency to develop
hypertension). Other contributing causes are obesity, smoking, alcoholism,
oral contraceptives or emotional stress.
Affected Population
Hypertension is a very common disorder affecting over 60 million Americans as
of 1988. Because there are rarely symptoms, many Americans are unaware they
have hypertension so these figures may be even higher.
Hypertension tends to occur more often in black people than in white;
however with age, the incidence of hypertension increase in all groups. Men
are affected more often than women before the age of 50; after 50, more women
are affected than men.
Therapies: Standard
Treatment of hypertension includes the use of diuretics (sometimes called
"water pills") to reduce sodium and water levels in the body and lower blood
pressure. Beta-blocking drugs which reduce constriction of blood vessels,
and vasodilators which are drugs that relax the muscles in blood vessel walls
are also used. Centrally acting drugs that lower the heart rate by
controlling the sympathetic nervous system, and angiotensin converting enzyme
(ACE) inhibitors which reduce constriction of blood vessels as well as salt
and water levels may be prescribed.
People can aid in the control of hypertension if they practice proper
weight control, exercise regularly and eat a low sodium diet. Blood pressure
machines for home use can be of benefit when people want to monitor their own
blood pressure.
Therapies: Investigational
There is extensive research being pursued on the causes, prevention and
treatment of hypertension. For information about this research contact the
National Heart, Blood and Lung Institute listed in the Resources section of
this report.
Clinical trials are underway to study the effects of dietary calcium and
sodium manipulation in Essential Hypertension. Interested persons may wish
to contact:
Dr. Rose Marie Robertson
Professor of Medicine
CC2218 MCN
Vanderbilt University
Nashville, TN 37232
(615) 322-2318
to see if further patients are needed for this research.
Clinical trials are underway to study patients that develop Supine
Hypertension after lesions of the nucleus tactus solitarii. Interested
persons may wish to contact:
S.H. Subramony, M.D.
University of Mississippi Medical Center
2500 N. State St.
Jackson, MS 39216
(601) 984-5525
to see if further patients are needed for this research.
Clinical trials are underway to study responses to psychologic stressors
in ten to eighteen year old patients with Primary Hypertension. Interested
persons may wish to contact:
Dr. Bruce S. Alpert
University of Tennessee
Division of Cardiology
848 Adams Ave.
Memphis, TN 38103
(901) 522-3380
to see if further patients are needed for this research.
This disease entry is based upon medical information available through
January 1990. Since NORD's resources are limited, it is not possible to keep
every entry in the Rare Disease Database completely current and accurate.
Please check with the agencies listed in the Resources section for the most
current information about this disorder.
Resources
For more information on Hypertension, please contact:
National Organization for Rare Disorders
P.O. Box 8923
New Fairfield, CT 06812-1783
(203) 746-6518
American Heart Association
7320 Greenville Ave.
Dallas, TX 75231
(214) 750-5300
NIH/National Heart, Blood, and Lung Institute
9000 Rockville Pike
Bethesda, MD 20892
(301) 951-3260
References
CECIL TEXTBOOK OF MEDICINE, 18th Ed.: James B. Wyngaarden, and Lloyd H.
Smith, Jr., Editors; W.B. Saunders Co., 1988. Pp. 276-302.
INTERNAL MEDICINE, 2nd Ed.: Jay H. Stein, ed.-in-chief; Little, Brown
and Co., 1987. Pp. 553.
THE MERCK MANUAL, Volume 1, 14th Ed.: Robert Berkow, M.D., ed.-in-chief;
Merck, Sharp, and Dohme Laboratories, 1982. Pp. 390-403.