Hyperkalemia
What is it?
Hyperkalemia is a high level of potassium in
the blood. Potassium is an electrolyte that is
important to the function of our nerve and muscle
cells, including the heart. (May also be spelled
hyperkalaemia.)
Who gets it?
Hyperkalemia is most common in people with
kidney disorders, especially those who do not
watch their potassium intake; the elderly, who are
experiencing age-related organ deterioration; and
people with diseases that affect kidney function.
What causes it?
Most of the body’s potassium is stored inside
various cells and organs, with only a small amount
found in the blood. The body maintains a balance
of potassium in the blood by matching the amount
of potassium we take in with the amount excreted
(put out) by the kidneys. Hyperkalemia occurs when
the kidneys aren’t excreting enough potassium from
the body. This could be caused by a disease that
affects kidney function, by eating large amounts
of potassium-rich foods, or by certain drugs used
to treat high blood pressure that cause the
kidneys to retain potassium rather than release
it. Addison’s disease, a disorder of the adrenal
glands, is also a cause of hyperkalemia. Sometimes
severe injury, such as muscle trauma or burns,
causes the cells and organs to release potassium
into the bloodstream in such large amounts that
the kidneys have difficulty excreting it, and this
causes hyperkalemia. Another cause of hyperkalemia
is acidosis, a condition in which too much acid in
the blood causes muscles to take up the excess
acid in exchange for a release of potassium into
the blood.
What are the symptoms?
Symptoms of hyperkalemia include irregular
heartbeat, which can range from mild to severe.
Severe cases can result in cardiac arrest.
Patients may feel muscle weakness or flaccid
paralysis (limpness), numbness in the feet or
hands, and skin tingling.
How is it diagnosed?
Hyperkalemia is diagnosed by measuring the
potassium levels in a blood sample. Normal blood
potassium levels are 3.5 to 5.0 milliequivalents
per liter (mEq/L) of blood. A patient with
hyperkalemia will have a blood potassium level
higher than 5.0 mEq/L. Your doctor may also order
a test called an electrocardiogram (ECG or EKG),
which measures the electrical activity of the
heart.
What is the treatment?
Severe hyperkalemia is treated with an
intravenous (IV) solution of insulin and glucose,
which causes the cells to absorb the excess
potassium from the blood. The solution may also
contain calcium to protect the heart from the
damaging effects of high potassium. Dialysis may
be required if the kidneys are failing. If
hyperkalemia is mild, your doctor will recommend a
diet low in potassium. He or she may also
recommend a special preparation called a
potassium-absorbing resin. This medication is
taken orally and enters the intestines where it
absorbs the excess potassium. The potassium then
leaves the body in the stool (bowel movement).
Self-care tips
If you have a disease that affects kidney
function or are taking drugs that affect the
kidneys’ ability to release potassium, it is
important to watch your potassium intake. Foods
high in potassium include bananas, oranges,
tomatoes, spinach and other green leafy
vegetables, melons, peas and beans, and potatoes.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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