Chloride
Electrolyte in the blood involved in fluid balance and acid-base balance
Also known as
Definition
Chloride is a negatively charged electrolyte that you take in mainly through table salt; the kidneys excrete any excess in the urine. It helps regulate the amount of fluid in the body, blood volume, blood pressure and the acid-base balance. It is usually measured together with sodium, potassium and bicarbonate in an electrolyte panel.
| Parameter | Value |
|---|---|
| Unit | mmol/L (mEq/L) |
| Reference Range | Typical for adults: 98–107 mmol/L. Labs differ slightly; the reference range on your own report is what counts. Discuss deviations with your doctor. |
Agree on your personal target range with your doctor.
For chloride, 1 mmol/L equals exactly 1 mEq/L because the ion carries a single charge. US reports usually give mEq/L.
↓ What a low value means
A low chloride level (hypochloremia) may be related to losses from prolonged vomiting or heavy sweating, as well as to heart failure, lung disease or metabolic alkalosis, meaning too much base in the blood. Hormonal causes such as hyperaldosteronism or Cushing syndrome are also possible. A single abnormal value does not automatically mean a condition that needs treatment; discuss it with your doctor.
↑ What a high value means
A high chloride level (hyperchloremia) may be related to kidney disease or metabolic acidosis, meaning too much acid in the blood. Other possible causes include diarrhea, certain medicines such as carbonic anhydrase inhibitors, and poisoning. Fluid intake, fluid losses and medicines such as antacids can also shift the value. Your doctor interprets it together with the other electrolytes.
When to test
Chloride is part of many routine and electrolyte panels. It is measured specifically with prolonged vomiting, diarrhea, dehydration, weakness, fatigue or breathing problems, and to monitor kidney, heart or liver disease and high blood pressure. Tell your practice about your medicines; you only need to fast if other tests in the same draw require it.
Frequently asked questions
Why is chloride almost always measured together with sodium? +
Like sodium, chloride comes mostly from table salt, and the two jointly regulate fluid balance. In an electrolyte panel they are therefore measured together with potassium and bicarbonate and interpreted as a group.
Can sweating change the chloride level? +
Heavy sweating is one of the possible causes of a low chloride level, as is prolonged vomiting. Very high fluid intake can also affect the value. Whether a deviation matters is something to clarify with your doctor.
Is there also a urine chloride test? +
Yes. Urine also contains chloride. A urine test can additionally show how much chloride the body excretes; your doctor decides whether it is useful.
Chloride
Sources
Last updated: October 05, 2026
This information is for orientation only and does not replace medical advice. Reference ranges can vary by laboratory, method and country.