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Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

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.

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In this Article

• What is is potassium?
• What are the causes of low potassium (hypokalemia)?
• What are the symptoms of low potassium?
• How is low potassium diagnosed?
• What is the treatment for low potassium?
• How can low potassium be prevented?
• Patient Comments: Low Potassium (Hypokalemia) - Diagnosis
• Patient Comments: Low Potassium - Symptoms and Signs
• Find a local Internist in your town
• Low Potassium (Hypokalemia) Index

Serum potassium levels above 3.0 mEq/liter are not considered dangerous or of great concern; they can be treated with potassium replacement by mouth. Depending on the patient's medical condition, other medical problems, and the patient's symptoms, serum levels lower than 3.0 mEq/liter may require intravenous replacement. Decisions are patient-specific and depend upon the diagnosis, the circumstances of the illness, and the patient's ability to tolerate fluid and medication by mouth.

Over the short-term, with self-limited illnesses like gastroenteritis with vomiting and diarrhea, the body is able to regulate and restore potassium levels on its own. However, if the hypokalemia is severe, or the losses of potassium are predicted to be ongoing, potassium replacement or supplementation may be required.

In those patients taking diuretics, often a small amount of oral potassium may be prescribed since the loss will continue as long as the medication is prescribed. Oral supplements may be in pill or liquid form, and the dosages are measured in mEq. Common doses are 10-20mEq per day. Alternatively, consumption of foods high in potassium may be the first option in replacing potassium. Bananas, apricots, oranges, and tomatoes are high in potassium content. Since potassium is excreted in the kidney, blood tests that monitor kidney function may be ordered to predict and prevent potassium levels from rising too high.

When potassium needs to be given intravenously, it must be given slowly. Potassium is irritating to the vein and is usually be given at a maximal rate of 10 mEq per hour. Moreover, infusing potassium too quickly can cause heart irritation and promote potentially dangerous rhythms such as ventricular tachycardia.

A Special Situation: Periodic Paralysis

Rarely, a special situation will occur when all the potassium in the body shifts from the serum into the cells of the body. This drops the serum potassium levels to 1.0 mEq/liter or lower. This causes immediate muscle weakness to the point that the patient cannot move. Arms and legs are most affected. Rarely, breathing and swallowing muscles can be involved.

Periodic paralysis may be hereditary and may be precipitated by excessive exercise, a high carbohydrate or high salt meal, or may occur without apparent cause.

Treatment by potassium replacement intravenously is effective, and recovery occurs within 24 hours.