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Emergency: requires immediate attention
Other Resources UpToDate PubMed
Emergency: requires immediate attention


Contributors: Shea A. Nagle MPH, Abhijeet Waghray MD
Other Resources UpToDate PubMed


Hypokalemia is a condition of low serum potassium (K+) concentration. The normal range of serum K+ is 3.5-5.0 mEq/L. This is one of the most common electrolyte derangements in the hospital setting. There is a broad differential for the underlying etiology of hypokalemia, but most causes fall within the broad categories of K+ losses, redistributive hypokalemia (influx of K+ to the intracellular space), or insufficient K+ intake.

Conditions that contribute to K+ losses are excessive K+ urinary output and prolonged vomiting or diarrhea. Other causes include laxative abuse, diuretics, salicylates, tumors (ie, VIPoma, villous adenoma), burns, malnutrition, alcohol use disorder, excessive sweating, jejunoileal bypass, and renal tubular disease. Chemotherapy and radiation as well as a variety of medication classes can contribute to excessive potassium loss. These include bronchodilators, caffeine, mineralocorticoids, glucocorticoids, and penicillin in high doses. Excessive consumption of natural licorice is a less common cause.

Conditions that contribute to increased transfer of potassium into the cells are excessive insulin, insulin administered with dextrose or glucose (rather than saline solution), refeeding syndrome, and other drug-induced agents that elevate beta-adrenergic activity. Additional causes include hypothermia, alkalosis, increased extracellular pH, and toxicity of chloroquine, barium, and similar agents. Hypokalemic periodic paralysis is an autosomal dominant inherited disorder that can cause episodic muscle weakness when K+ levels are low.

Conditions that contribute to decreased K+ intake include potassium-deficient diet, parenteral therapy, and malnutrition. These conditions are usually seen in combination with other factors in patients with hypokalemia.


E87.6 – Hypokalemia

43339004 – Hypokalemia

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Differential Diagnosis & Pitfalls

Potential factors associated with hypokalemia include the following.

  • Vomiting
  • Diarrhea
  • Laxative use
  • Fistula
  • Tumor – villous adenoma
  • Refeeding syndrome
  • Insufficient potassium absorption – jejunoileal bypass
  • Low potassium intake – Malnutrition, parenteral nutrition
Renal / electrolyte abnormality:
  • Renal tubular acidosis – Distal renal tubular acidosis or Proximal renal tubular acidosis
  • Primary aldosteronism – primary or secondary
  • Malignant hypertension
  • Hypomagnesemia
  • Profuse perspiration
  • Bartter disease
  • Gitelman syndrome
  • Liddle syndrome
  • Fanconi anemia and Acquired Fanconi syndrome
  • EAST syndrome (epilepsy, ataxia, sensorineural deafness, and salt-wasting renal tubulopathy)
  • Familial hypokalemic periodic paralysis
Endocrine / metabolic:
  • Metabolic alkalosis / alkalemia
  • Hyperthyroidism
  • Cushing syndrome
  • Diabetic ketoacidosis – secondary to treatment with insulin
  • Hypothermia
  • Tumors – Vasoactive intestinal peptide-secreting tumor (WDHA syndrome [watery diarrhea, hypokalemia, and achlorhydria]), Insulinoma
Medications / other substances – see Drug Reaction Data below for more information.

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Drug Reaction Data

Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.

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Last Reviewed:07/25/2019
Last Updated:01/31/2023
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Emergency: requires immediate attention
A medical illustration showing key findings of Hypokalemia (Moderate) : Diarrhea, Fatigue, Vomiting, Muscle weakness, Muscle cramp, K decreased
Copyright © 2024 VisualDx®. All rights reserved.