Podcast 1016: Hypokalemia

Contributor: Meghan Hurley, MD

Educational Pearls:

What is hypokalemia?

Hypokalemia is when the measured blood level of potassium falls below 3.5 mEq/L (normal 3.5 - 5.2 mEq/L).

Can generally be considered in mild (3.0 - 3.5 mEq/L); moderate (2.5 - 2.9 mEq/L); and severe ( Should be noted that blood levels of potassium can be low while total body potassium is normal due to intracellular shift by certain agents like β-2 agonists (e.g. Albuterol) or insulin. There is no appreciable loss of insulin despite hypokalemia being present in labs.

What are the most common causes of hypokalemia?

Medications are a predominant cause; mainly loop and thiazide diuretics.

Gastrointestinal losses such as prolonged emesis or diarrhea (can occur in the setting of chronic illness and treatment such as chemotherapy patients with emesis).

Other renal losses (e.g. hyperaldosteronism and renal tubular acidosis).

A fun-fact renal loss: A compound found in some licorice (Glycyrrhizic acid) can inhibit 11-ß-hydroxysteroid dehydrogenase enzyme type 2 and cause mineralocorticoid excess. See a 2023 case study in references for Lethal Arrhythmia Induced by Licorice.

What is a less common cause of hypokalemia?

Hypokalemic Periodic Paralysis (HypoPP) is a genetic autosomal dominant channelopathy where patients leak potassium at rest causing a flaccid paralysis of muscle.