Chloride

Chloride is an electrolyte that works closely with sodium to maintain fluid balance and, along with bicarbonate, to keep your blood's acid-base status in check. It's a routine part of the basic metabolic panel and usually tracks sodium, so it moves up or down for many of the same reasons. On its own it's rarely the focus, but it helps round out the electrolyte picture.

The typical reference range is about 96 to 106 mmol/L (reported as mEq/L on many US panels, the same number). High chloride is often seen with dehydration or certain acid-base disorders, while low chloride can accompany vomiting or metabolic alkalosis. Compare your value to the range on your own report.

A chloride a point or two outside the range is usually not meaningful by itself and is most often explained by hydration or how it pairs with sodium and bicarbonate. Doctors interpret chloride together with the rest of the electrolytes and the anion gap rather than in isolation. A persistent abnormality, or one paired with other off values, is worth reviewing with your physician.