|See Also||Lab Tests|
Chloride is considered to be the principle extracellular anion. It is found in the form of sodium chloride or hydrochloric acid within extracellular spaces. Aldosterone, which is responsible for increased reabsorption of sodium from the kidney, is also responsible for the reabsorption of chloride. Chloride levels normally change in direct relationship to sodium. Hence if serum sodium is decreased, a decreased chloride level can be expected. However, chloride levels have an inverse relationship to CO2 levels. ,
- Chloride plays a role in influencing osmotic pressure and acid-base balance, thereby helping maintain cellular integrity.
- Chloride ions are normally lost from the stomach, along with other cations such as sodium and potassium, during bouts of vomiting and/or diarrhea.
- No fasting is required.
- Factors which can cause increased levels
- high plasma chloride levels normally found in infants, short term increases after saline IV infusions
- Drugs: acetazolamide, ammonium chloride, androgens, chlorothiazide, cortisone preparations, estrogens, guanethidine, hydrochlorothiazide, methyldopa, and nonsteroidal antiinflammatory drugs.
- Factors which can cause decreased levels:
- Drugs: aldosterone, bicarbonates, corticosteroids, cortisone, hydrocortisone, loop diuretics, thiazide diuretics, and triamterene.
Ranges: The following are the reference ranges for this lab. However, lab ranges can vary by laboratory and country. 
|Standard U.S. Units||Standard International Units|
|Conventional Laboratory Range||97- 107 mEq/L||97- 107 mmol/L|
|Optimal Range||100-106 mEq/L||100-106 mmol/L|
|Alarm Ranges||<90 or >115 mEq/L||<90 or >115 mmol/L|
High levels indicate:
- Metabolic acidosis
- Adrenal hyperfunction
- Other conditions: excess salt intake, adrenal hyperfunction, dehydration, parathyroid hyperfunction, Cushing's syndrome, hyperventilation (respiratory alkalosis), diabetes insipidus, renal tubular acidosis
Low levels indicate:
- Metabolic alkalosis
- Adrenal hypofunction
- Other conditions: pyloric spasm or obstruction, over-hydration, renal dysfunction, constipation, respiratory distress COPD or CHF, diabetes, Addison's Disease, prolonged vomiting
- Pagana Kathleen D, Pagana Timothy J, (1998) Mosby's Manual of Diagnostic and Laboratory Tests, Mosby, Inc
- Weatherby Dicken, Ferguson Scott (2002) Blood Chemistry and CBC Analysis: Clinical Laboratory Testing from a Functional Perspective, Bear Mountain