Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Hyperkalemia is common; it is diagnosed in up to 8% of
hospitalized patients in the U.S. Fortunately, most patients have mild
hyperkalemia (which is usually well tolerated). However, any
condition causing even mild
hyperkalemia should be treated to prevent progression into more severe
hyperkalemia. Extremely high levels of potassium in the blood (severe
hyperkalemia) can lead to cardiac arrest and
death. When not recognized and treated properly, severe hyperkalemia results in
a mortality rate of about 67%.
Technically, hyperkalemia means an abnormally elevated level of potassium in the blood.
The normal potassium level in the blood is 3.5-5.0 milliequivalents per liter
(mEq/L). Potassium levels between 5.1 mEq/L to 6.0 mEq/L reflect mild hyperkalemia.
Potassium levels of 6.1 mEq/L to 7.0 mEq/L are moderate hyperkalemia, and levels
above 7 mEq/L are severe hyperkalemia.
How does hyperkalemia affect the body?
Potassium is critical for the normal functioning of the
muscles, heart, and
nerves. It plays an important role in controlling activity of smooth muscle (such as
the muscle found in the digestive tract) and skeletal muscle (muscles
of the extremities and torso), as well as the muscles of the heart. It is also
important for normal transmission of electrical signals throughout the nervous
system within the body.
Normal blood levels of potassium are critical for maintaining normal heart
electrical rhythm. Both low blood potassium levels (hypokalemia) and high
blood potassium levels (hyperkalemia) can lead to
abnormal heart rhythms.
The most important clinical effect of hyperkalemia is
related to electrical rhythm of the heart. While mild hyperkalemia probably has
limited effect on the heart, moderate hyperkalemia can produce EKG changes (EKG
is an electrical reading of the heart muscles), and severe hyperkalemia can
cause suppression of electrical activity of the heart and can cause the heart to
Another important effect of hyperkalemia is interference
with functioning of the skeletal muscles. Hyperkalemic periodic paralysis is
inherited disorder in which patients can develop sudden onset of hyperkalemia which in turn causes
muscle paralysis. The reason for the muscle paralysis is not clearly understood,
but it is probably due to hyperkalemia suppressing the electrical activity of
What Are Some of the Causes of Hyperkalemia (High Blood Potassium)
Excess potassium in the bloodstream can result from diseases of the kidneys or adrenal glands as well as from certain medications. Hyperkalemia can also be the result of potassium moving out of its usual location within cells into the bloodstream.
Any condition in which there is massive tissue destruction can result in elevated levels of blood potassium as the damaged cells release their potassium. Examples of tissue destruction include: