Chloride
Also written as: Cl
An electrolyte that partners with sodium, used to assess fluid balance and the acid-base status of the blood.
What it measures
The concentration of chloride, one of the main electrolytes in the blood. Chloride travels closely with sodium and helps maintain fluid balance and the acid-base balance of the body.
Why a doctor orders it
It is part of the standard electrolyte panel rather than a test usually ordered on its own. Clinicians use it together with sodium and bicarbonate to judge hydration and to detect disturbances in the body's acid-base balance.
What is generally associated with a higher result
Broadly associated with dehydration, certain kidney conditions, and acid-base disturbances in which the blood becomes more acidic. It can also rise after large volumes of saline intravenous fluid.
What is generally associated with a lower result
Broadly associated with fluid loss from prolonged vomiting, diuretic use (water tablets), and conditions in which bicarbonate is raised. Small deviations are common and generally interpreted only in context with the other electrolytes.
Everyday things that move this number
Not every shift in a value reflects disease. These are ordinary factors known to affect this particular measurement:
- Hydration status on the day of the draw
- Recent vomiting or diarrhea
- Diuretic medications
- Drinking very large amounts of water
- Recent intravenous fluids
Questions to take to your appointment
- Does my chloride fit with my sodium and bicarbonate, or is something called the anion gap worth calculating?
- Could a diuretic or another medication I take explain this value?
- Could recent illness with vomiting or diarrhea account for it?
Build a printable questionnaire with your own results →
Where to read more
MedlinePlus, from the US National Library of Medicine, publishes patient-facing pages on individual lab tests and is a reliable next stop: medlineplus.gov/lab-tests .
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