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$Unique_ID{BRK03851}
$Pretitle{}
$Title{Hypokalemia}
$Subject{Hypokalemia Hypokalemic Syndrome Hypopotassemia Syndrome Nephritis
Potassium-Losing Potassium Loss Low Potassium Bartter's Syndrome Periodic
Paralysis Hypokalemic Type Alkalosis Metabolic }
$Volume{}
$Log{}
Copyright (C) 1990 National Organization for Rare Disorders, Inc.
748:
Hypokalemia
** IMPORTANT **
It is possible that the main title of the article (Hypokalemia) is not
the name you expected. Please check the SYNONYM listing to find the
alternate names and disorder subdivisions covered by this article.
Synonyms
Hypokalemic Syndrome
Hypopotassemia Syndrome
Nephritis, Potassium-Losing
Potassium Loss
Low Potassium
Information on the following diseases can be found in the Related
Disorders section of this report:
Bartter's Syndrome
Periodic Paralysis, Hypokalemic Type
Alkalosis, Metabolic
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.
Hypokalemia is a metabolic imbalance characterized by extremely low
potassium levels in the blood. It is a symptom of another disease or
condition, or a side effect of diuretic drugs. The body needs potassium for
the contraction of muscles (including the heart), and for the functioning of
many complicated proteins (enzymes). Potassium is found primarily in the
skeletal muscle and bone, and participates with sodium to contribute to the
normal flow of body fluids between the cells in the body. The normal
concentration of potassium in the body is regulated by the kidneys through
the excretion of urine. When the kidneys are functioning normally, the
amount of potassium in the diet is sufficient for use by the body and the
excess is usually excreted through urine and sweat. Body chemicals and
hormones such as aldosterone also regulate potassium balance. Secretion of
the hormone insulin, which is normally stimulated by food, prevents a
temporary diet-induced Hypokalemia by increasing cell absorption of
potassium. When Hypokalemia occurs, there is an imbalance resulting from a
dysfunction in this normal process, or the rapid loss of urine or sweat
without replacement of sufficient potassium.
Symptoms
Symptoms of hypokalemia may include attacks of severe muscle weakness,
eventually leading to paralysis and possibly respiratory failure. Muscular
malfunction may result in paralysis of the bowel, low blood pressure, muscle
twitches and mineral deficiencies (tetany). Severe hypokalemia may also lead
to disruption of skeletal muscle cells, particularly during exercise. The
normal physical response to exercise requires the local release of potassium
from muscle. In potassium depleted muscle, the lack of potassium prevents
adequate widening of blood vessels, resulting in decreased muscle blood flow,
cramps and the destruction of skeletal muscle.
Hypokalemia may also impair the ability of the kidneys to concentrate
urine, resulting in excessive urination (polyuria) and excessive thirst
(polydipsia). Other symptoms may include loss of appetite, nausea and
vomiting. There may also be heart irregularities seen in electrocardiograph
changes, confusion, distention of the abdomen, a decrease in mental activity.
Causes
Hypokalemia always occurs as a result of excessive loss of potassium through
the urine, sweat or stool. It is always a symptom of another disorder,
rather than a disease that occurs by itself.
The excessive excretion of potassium in the urine (kaliuresis) may result
from the use of diuretic drugs (which increases urination), a deficiency of
magnesium in the blood, excessive mineralocorticoids such as aldosterone in
the blood which affect the electrolyte and fluid balance in the body (usually
caused by endocrine diseases), kidney disorders, or from the use of high
doses of penicillin. Gastrointestinal losses of potassium usually are due to
prolonged diarrhea or vomiting, chronic laxative abuse, inadequate dietary
intake of potassium, intestinal obstruction or infections such as fistulas in
the intestines which continually drain intestinal fluids. Additionally,
excessive perspiration due to hot weather or exercise can cause hypokalemia.
Affected Population
Hypokalemia may affect both males and females. However, it occurs more
commonly in females.
Related Disorders
Symptoms of the following disorders include Hypokalemia. Comparisons may be
useful for a differential diagnosis:
Bartter's Syndrome is a metabolic disorder involving the kidneys. Major
symptoms include slowed growth, weakness, excessive thirst and excessive
urination. Bartter's Syndrome is characterized by the excessive loss of
potassium through the kidneys. (For more information on this disorder,
choose "Bartter" as your search term in the Rare Disease Database).
Periodic Paralysis, Hypokalemic Type, is a disorder characterized by
episodes of paralysis with loss of deep tendon reflexes and failure of
muscles to respond to electrical stimulation. The cause is unknown. The
paralysis may be limited to certain muscle groups or it may affect all four
limbs. The attacks usually last between 24 and 48 hours. Potassium levels
are usually abnormally low (hypokalemia).
Metabolic Alkalosis is a disorder characterized by an increase in blood
bicarbonate. Symptoms include irritability, neuromuscular hyperexcitability,
low blood potassium (hypokalemia), muscular weakness, impaired
gastrointestinal motility and excessive urination.
(To find other disorders that include Hypokalemia as a symptom, choose
"Hypokalemia" as your search term in the Rare Disease Database.)
Therapies: Standard
The underlying cause of Hypokalemia must first be treated. When the
hypokalemia is severe, potassium chloride may be administered orally or
intravenously. Treatment must be carefully monitored by a physician. Any
associated acid-base disorders or hormonal disturbances must be evaluated
before treatment is planned. The administration of potassium and potassium-
sparing diuretics is usually discouraged in patients with kidney disease,
diabetes mellitus, or dysfunctions of the autonomic nervous system. The
imbalance of external and internal potassium levels in these individuals may
predispose them to life-threatening degrees of Hyperkalemia (too much
potassium). Hypokalemia in individuals with high blood pressure taking
diuretics may be improved by replacing lost potassium in the diet through
certain fruits or potassium drugs. Hypokalemia may also be minimized by
dietary restriction of salt since high rates of sodium excretion promote
urinary potassium losses. People who participate in vigorous sports or
exercise in warm weather should be sure to replace potassium that is lost
through excessive sweating. This can be accomplished through dietary
planning.
Therapies: Investigational
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 Hypokalemia, please contact:
National Organization for Rare Disorders (NORD)
P.O. Box 8923
New Fairfield, CT 06812-1783
(203) 746-6518
National Digestive Diseases Information Clearinghouse
Box NDDIC
Bethesda, MD 20892
(301) 468-6344
References
INTERNAL MEDICINE, 2nd Ed.: Jay H. Stein, ed.-in-chief; Little, Brown and
Co., 1987. Pp. 815-820.
THE MERCK MANUAL, Volume 1, 14th Ed.: Robert Berkow, M.D., ed.-in-
chief;Merck Sharp & Dohme Laboratories, 1982. Pp. 966-969.
PHYSIOLOGY OF MAGNESIUM METABOLISM AND THE IMPORTANT ROLE OF MAGNESIUM IN
POTASSIUM DEFICIENCY. R.K. Rude; AM J CARDIOL (April 18, 1989; issue 63
(14)). Pp. 31G-34G.
ALDOSTERONE-PRODUCING ADENOMA PRESENTING WITH HYPOKALEMIC MYOPATHY. B.A.
Dickson et al.; CLIN PEDIATR (PHIL) (July, 1988; issue 27 (7)). Pp. 344-347.