Sign in →

Test Code NA Sodium, LAB122


Indirect Potentiometric

Performing Laboratory

St. Luke's Hospital Cedar Rapids

Specimen Requirements


Preferred: Green-top (lithium heparin) tube-Sodium heparin tube is not acceptable.

Acceptable: Gold-top serum gel tube or plain red-top tube
Specimen Volume: 0.1 mL of plasma or serum

Stability: Sodium in serum and plasma are stable for at least one week either at room

               or refrigerator (2-8ºC) temperature and for at least one year frozen.


Reference Values

136-145 mmol/L

Critical values

0-30 days: <125 mmol/L or >150 mmol/L

≥1 month: <120 mmol/L or >160 mmol/L

Day(s) Test Set Up

Monday through Sunday

Test Classification and CPT Coding


Useful For

Sodium measurements are used in the diagnosis and treatment of aldosteronism (excessive secretion of the hormone aldosterone), diabetes insipidus (chronic excretion of large amount of dilute urine, accompanied by extreme thirst), adrenal hypertension, Addison’s disease (caused by destruction of the adrenal glands), dehydration, inappropriate antidiuretic hormone secretion, or other diseases involving electrolyte imbalance.