Chloride

Measured in mmol/L

An electrolyte that generally moves in step with sodium and is most informative as part of the acid-base picture rather than on its own.

What it is

Chloride is an electrolyte that usually tracks closely with sodium and helps your body maintain fluid balance and the right acidity (pH) of your blood. It's rarely interpreted alone — clinicians typically read it together with sodium, potassium, and CO2/bicarbonate, sometimes using them to calculate something called the anion gap, a quick check on acid-base balance. Like other electrolytes, it can shift with hydration, vomiting or diarrhea, and certain medications, so small movements are common and are read in the context of the whole panel.

Typical range

  • Adults98–107 mmol/L

Source · Mayo Clinic Laboratories (CL) (2026)

Reference ranges vary between laboratories, and what is normal for you depends on your own history. Your own lab’s range is the one printed on your report.

Worth asking your clinician

  • How does my chloride fit with the rest of my electrolyte results?
  • Is this value something you'd consider expected for me, or worth a closer look?
  • Could recent illness, hydration, or my medications explain this result?