Chloride blood test (Cl)
98–107 mEq/l or mmol/l (the numerical value is the same)
- Updated
- 2026-09-30
- Every number with its source
What chloride is and what it does
Chloride (Cl⁻) is an electrolyte — an ion carrying an electrical charge, dissolved in blood plasma and the body's fluids. Together with sodium and potassium ions, chloride helps keep the right amount of fluid inside cells and around them, and it also takes part in regulating the acid-base balance of the blood. Most of the chloride in the body comes in with table salt (sodium chloride). The amount of chloride in blood usually changes together with the amount of sodium, so the test is most often done as part of an electrolyte or biochemical (metabolic) blood panel rather than on its own. Deviations from the normal range may point to fluid loss, kidney or lung disease, hormonal disorders or a disturbance of the acid-base balance, so the result is always worth assessing together with the other electrolytes and the overall clinical picture.
Reference range
| Group | Range, mmol/l | Source |
|---|---|---|
| Adults 98–107 mEq/l or mmol/l (the numerical value is the same) | 98–107 | MedlinePlus Reviewed 2025-05-19 |
MedlinePlus gives this value for adults. Laboratory intervals differ slightly — the Norwegian laboratory Fürst, for example, gives 97–108 mmol/l and the Helse Møre og Romsdal hospital laboratory 95–105 mmol/l — so it is important to look at the range printed on your own report — see also how to read blood test results.
When chloride is tested
- During a routine general health check-up — most often as part of an electrolyte or biochemical (metabolic) blood panel
- When a disturbance of the body's fluid or acid-base balance is suspected
- When there is vomiting or diarrhoea over a long period
- With tiredness, weakness, dehydration or breathing problems
- To monitor the course of a kidney, heart or lung disease, or the effect of its treatment
How to prepare
- Some medicines can affect the result of the test — a doctor may ask you not to take them for a while before the test; do not stop or change your medicines without talking to your doctor first
- In some cases you may be asked not to eat or drink for a few hours before the test
A raised result (hyperchloraemia)
A raised chloride level (hyperchloraemia) may be linked to kidney disease or diarrhoea, and it can also indicate metabolic acidosis — a state in which there is too much acid in the blood. Other causes are Addison's disease, poisoning with ethylene glycol or methanol, and certain medicines. The MedlinePlus lab-tests page also lists dehydration as a possible cause. The other electrolytes and a blood gas test help to work out the cause. The causes listed are:
- Kidney disease
- Diarrhoea
- Metabolic acidosis, including lactic acidosis and renal tubular acidosis
- Addison's disease (adrenal insufficiency)
- Poisoning with ethylene glycol or methanol
- Medicines from the carbonic anhydrase inhibitor group
- Toxic effect of salicylates (the aspirin group)
- Compensated respiratory alkalosis
- Dehydration
- Hypertonic dehydration (for example in diabetes insipidus) and acute kidney failure — listed by the Norwegian laboratory Fürst
What is usually assessed alongside a raised result:
- The other electrolytes (sodium, potassium, bicarbonate) and a blood gas test — they help assess the acid-base state
- Fluid balance and hydration status
- Kidney function markers (creatinine, urea)
- Whether any medicines that could affect the result are being taken
A low result (hypochloraemia)
A low chloride level (hypochloraemia) may be linked to vomiting or excessive sweating, and it can also indicate heart failure or metabolic alkalosis. The MedlinePlus lab-tests page additionally lists lung disease and Addison's disease as possible causes. The causes listed are:
- Prolonged vomiting
- Burns
- Heart failure
- Cushing's syndrome
- Dehydration
- Heavy sweating
- Hyperaldosteronism
- Metabolic alkalosis
- Compensated respiratory acidosis
- SIADH (syndrome of inappropriate antidiuretic hormone secretion)
- Lung disease
- Addison's disease
- Treatment with diuretics (water tablets) and pyloric stenosis (narrowing of the stomach outlet) — listed by the Norwegian laboratory Fürst
What is usually assessed alongside a low result:
- The other electrolytes (sodium, potassium, bicarbonate) and a blood gas test
- The cause of the fluid loss — vomiting, sweating
- Assessment of heart, kidney and adrenal function
- Whether any diuretic or other medicines that affect the result are being taken
Related tests
Chloride is rarely tested on its own — most often it is measured together with sodium, potassium and bicarbonate within an electrolyte or biochemical (metabolic) panel, because together these markers reflect the fluid and acid-base state. Related pages: sodium, potassium, bicarbonate, calcium, magnesium.
Full site in Lithuanian: proactiva.app
Frequently asked questions
›What is the normal chloride level in blood?
According to MedlinePlus, the normal chloride value in adults is 98–107 mmol/l (or mEq/l — the numerical value is the same). Laboratory intervals differ slightly: the Norwegian laboratory Fürst, for example, gives 97–108 mmol/l and the Helse Møre og Romsdal hospital laboratory 95–105 mmol/l. So it is important to look at the range printed on your own report.
›Why is a chloride test done?
A chloride test is most often done as part of a routine health check-up or an electrolyte (biochemical blood) panel, and also when a disturbance of the body's fluid or acid-base balance is suspected.
›Why can chloride be raised?
A raised chloride level may be linked to kidney disease or diarrhoea, and it can also indicate metabolic acidosis. The other electrolytes and a blood gas test help to establish the exact cause — this is worth discussing with a doctor.
›Why can chloride be low?
A low chloride level may be linked to prolonged vomiting or heavy sweating, and also to heart failure or metabolic alkalosis. A doctor assesses the cause together with the other tests.
›Is any special preparation needed before a chloride test?
In some cases a doctor may ask you not to eat or drink for a few hours before the test, or to stop taking certain medicines for a while — it depends on which other tests the chloride is being done with. Do not stop or change your medicines without talking to your doctor first.
›Is the chloride test done on its own?
Rarely — chloride is most often tested together with sodium, potassium and bicarbonate within an electrolyte or biochemical (metabolic) panel, because together these markers reflect the fluid and acid-base state. The chloride value is also used to calculate the anion gap, which is used when acid-base disorders are investigated (Helse Møre og Romsdal laboratory description).
Sources
- MedlinePlus (US National Library of Medicine): Chloride test - blood — 2026-09-06
- MedlinePlus (US National Library of Medicine): Chloride Blood Test — 2026-09-11
- Fürst Medical Laboratory (Norway): S-Klorid — 2026-09-29
- Helse Møre og Romsdal, Department of Medical Biochemistry (Norway): Klorid (P/S-Klorid) — 2026-09-29
Related markers
This site is not an emergency service. If severe chest or head pain, breathlessness, confusion, difficulty speaking, heavy bleeding or another acute problem has come on suddenly — do not wait for tests, call 112.
This information is not a diagnosis and does not replace a consultation with a doctor. Reference ranges depend on the laboratory, your age and sex — always compare your result with the range printed on your own report.