Sodium, Blood is a topic covered in the Davis's Lab & Diagnostic Tests.

To view the entire topic, please or purchase a subscription.

Davis’s Laboratory and Diagnostic Tests Online, powered by Unbound Medicine, provides nurses and students access to 400+ test monographs containing reference ranges, indications, patient preparation and result interpretation. Explore these free sample topics:


-- The first section of this topic is shown below --


Serum Na+.

Common Use:
To assess electrolyte balance related to hydration levels and disorders such as diarrhea and vomiting and to monitor the effect of diuretic use.

Serum collected in a gold-, red-, or red/gray-top tube. Plasma collected in a green-top (heparin) tube is also acceptable.

Normal Findings:
(Method: Ion-selective electrode)

AgeConventional & SI Units
Cord126–166 mEq/L or mmol/L
1–12 hr124–156 mEq/L or mmol/L
12–24 hr132–159 mEq/L or mmol/L
24–48 hr134–160 mEq/L or mmol/L
48–72 hr139–162 mEq/L or mmol/L
Newborn135–145 mEq/L or mmol/L
7 d–1 mo134–144 mEq/L or mmol/L
2 mo–5 mo134–142 mEq/L or mmol/L
6 mo–1 yr133–142 mEq/L or mmol/L
Child–Adult–older adult135–145 mEq/L or mmol/L
Note: Older adults are at increased risk for both hypernatremia and hyponatremia. Diminished thirst, illness, and lack of mobility are common causes for hypernatremia in older adults. There are multiple causes of hyponatremia in older adults, but the most common factor may be related to the use of thiazide diuretics.

-- To view the remaining sections of this topic, please or purchase a subscription --