Chloride - Kresser Institute Membership Site

REFERENCE RANGES FOR SERUM CHLORIDE:

Laboratory reference range: 97–108 mmol/L

Functional reference range: 100–106 mmol/L

DESCRIPTION:

Chloride is one of the body’s main electrolytes. The anion is found throughout the body, although the blood contains particularly high levels. Cellular processes keep extracellular concentrations of chlorine higher than intracellular concentrations.¹ With sodium, chloride maintains osmotic pressure and water balance and contributes to serum osmolality.^2,3 Chloride also participates in acid–base homeostasis, acting as a buffer and maintaining the proper electrical gradient across cell membranes.^3-5

Substantial amounts of chloride are consumed in the diet. Chloride is freely absorbed by the gut and freely filtered by the kidney.⁵ Like sodium, most chloride is reabsorbed by the kidney.⁶ As such, the level of chloride in blood usually moves in the same direction and in proportion to sodium.⁴ In pathological conditions, however, such as acid–base disorders, chloride levels can change independently from sodium.⁴ Bicarbonate–chloride transporters and chloride channels in renal tubules change serum levels of chloride in response to acid–base disturbances.⁶

Hyperchloremia, which is an abnormally high concentration of chloride in the blood, may occur in several conditions.⁷ Hyperchloremia often occurs with hypernatremia, but concomitant elevations do not always occur. Excess ingestion (e.g., saltwater drowning) or administration of sodium chloride (e.g., hypertonic saline infusion) can cause hyperchloremia and hypernatremia, as can free water loss or hypotonic dehydration (e.g., diabetes insipidus).⁷ Hypernatremia itself may drive hyperchloremia. Hyperchloremia without hypernatremia is often caused by an acid–base disturbance, usually hyperchloremic metabolic acidosis. Hyperchloremic metabolic acidosis has multiple causes, from early kidney failure to severe diarrhea. Various drugs, including carbonic anhydrase inhibitors, are known to cause hyperchloremic metabolic acidosis.

Hypochloremia is an abnormally low serum chloride level. The etiology of hypochloremia is often grouped into renal and extrarenal causes.⁷ Renal chloride losses may occur from diuretic abuse, interstitial nephritis, chronic renal failure, and adrenal insufficiency. Extrarenal causes of hypochloremia may be caused by total body chloride depletion, dilution, and acid–base abnormalities. Chloride may be depleted by inadequate intake or excessive losses. Serum chloride is diluted by a relative increase in other substances, such as free water. Dilutional causes of hypochloremia include states such as nephrosis, syndrome of inappropriate antidiuretic hormone (SIADH), and pathological polydipsia (excess water consumption). Metabolic acidosis can result in decreased serum chloride, as can compensated respiratory acidosis.

Serum chloride is virtually always measured along with other components of the basic metabolic panel or comprehensive metabolic panel.⁸ Chloride may also be measured in the urine or on the arm, as part of a chloride sweat test.

PATHOLOGICAL/CONVENTIONAL RANGE INDICATIONS:

High in:^2,10

Dehydration
Kidney disease
- Early renal failure
- Interstitial renal disease
- Nephrotic syndrome
- Renal tubular acidosis
Acid–base disturbance
- Metabolic acidosis
- Bicarbonate loss (e.g., small bowel diarrhea)
- Hypernatremia
- Respiratory alkalosis
Hormonal conditions
- Diabetes insipidus
- Mineralocorticoid deficiency
- Hyperparathyroidism
Saltwater ingestion
Hypertonic saline administration
Drugs
- Acetazolamide
- Ammonium chloride
- Androgens
- Arginine or lysine hydrochloride
- Bromine intoxication
- Estrogens
- Hydrochlorothiazide
- Iodine intoxication
- Salicylate intoxication

Low in:^2,¹²

Inadequate NaCl intake
Acid–base abnormalities
- Compensated respiratory acidosis
- Metabolic alkalosis (e.g., vomiting, nasogastric suctioning)
Hormonal conditions
- Adrenal insufficiency
- Hypothyroidism
- Syndrome of inappropriate antidiuretic hormone (SIADH)
Congestive heart failure
Liver cirrhosis
Nephrotic syndrome
Interstitial nephritis
Small bowel fistulas
Hyperglycemia (early)
Pathological polydipsia
Drugs
- Barbiturates
- Chlorpropamide
- Clofibrate
- Diuretic abuse
- Morphine
- Nicotine
- Tricyclics

FUNCTIONAL RANGE INDICATIONS:

High in:

Same as conventional indications

Low in:

Same as conventional indications

References: