• A relative excess of chloride has been linked with [1]:

    • Reduced renal blood flow
    • Increased interstitial renal and gastrointestinal edema
    • Reduced survival in patients with acute kidney injury
    • Increased morbidity and mortality in critically ill patient
  • Chloride is the most abundant anion in the extracellular fluid compartment.

  • The primary drivers of chloride homeostasis are:

    • Passive equilibration with sodium
    • Chloride-bicarbonate anion exchange in the kidney, such that bicarbonate excretion is exchanged for chloride resorption (and vice versa)
  • In general, hyperchloremia is a reflection of either hypernatremia and/or an acid-base disorder.

Causes [1]

Special Populations


There are no pediatric-specific causes for hyperchloremia. Similar to the adult population, abnormally high chloride levels are an independent predictor of higher morbidity and mortality in the setting of septic shock [6].

The chloride value in hyperchloremia are slightly different than for adults [7].

Pediatric AgeHyperchloremia definition
Premature infantCl >110 mEq/L
NewbornCl >106 mEq/L
ChildCl >110 mEq/L


There are no pregnancy-specific causes for hyperchloremia. A 2009 review suggests that the definition of hyperchloremia in first trimester should use a lower cutoff than the other two trimesters [8].

Trimester StageHyperchloremia definition
FirstCl >105 mEq/L
SecondCl >109 mEq/L
ThirdCl >109 mEq/L

Originally published Feb 12, 2023 (updated February 13, 2023)


  1. Nagami GT. Hyperchloremia – Why and how. Nefrologia. 2016;36(4):347-353. doi:10.1016/j.nefro.2016.04.001. PMID 27267918
  2. Sharma S, Hashmi MF, Aggarwal S. Hyperchloremic Acidosis. [Updated 2022 Aug 18]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan.
  3. Pham AQ, Xu LH, Moe OW. Drug-Induced Metabolic Acidosis. F1000Res. 2015;4:F1000 Faculty Rev-1460. Published 2015 Dec 16. doi:10.12688/f1000research.7006.1. PMID 26918138
  4. Buisman L, Riphagen IJ, Kwant M, Themmen MD, Bouma M, Bethlehem C. Case report: Salicylate intoxication can present with a normal anion gap metabolic acidosis depending on method used for measuring chloride. Br J Clin Pharmacol. 2022;88(11):4933-4936. doi:10.1111/bcp.15492. PMID 35971785
  5. Munekawa C, Kawasaki T, Miyoshi T, Yamane Y, Okada H, Oyamada H. Acute Bromide Intoxication in a Patient with Preserved Renal Function. Am J Case Rep. 2020;21:e922019. Published 2020 Apr 8. doi:10.12659/AJCR.922019. PMID 32265433
  6. Stenson EK, Cvijanovich NZ, Anas N, et al. Hyperchloremia Is Associated With Complicated Course and Mortality in Pediatric Patients With Septic Shock. Pediatr Crit Care Med. 2018;19(2):155-160. doi:10.1097/PCC.0000000000001401. PMID 29394222
  7. Pagana KD, Pagana TJ, Pagana TN. Mosby’s Diagnostic and Laboratory Test Reference. 14th ed. St. Louis, MO: Elsevier; 2019.
  8. Abbassi-Ghanavati M, Greer LG, Cunningham FG. Pregnancy and laboratory studies: a reference table for clinicians. Obstet Gynecol. 2009 Dec;114(6):1326-1331. doi: 10.1097/AOG.0b013e3181c2bde8. Erratum in: Obstet Gynecol. 2010 Feb;115(2 Pt 1):387. PMID: 19935037.


Lopes G, Lin M. Lab It Up: Hyperchloremia. Academic Life in Emergency Medicine. https://www.aliem.com/lab-it-up-hyperchloremia/. Feb 12, 2023.

Gabriella Lopes, MD

Gabriella Lopes, MD

Emergency Medicine Resident
Department of Emergency Medicine
University of California, San Francisco
Gabriella Lopes, MD

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