Serum sodium

Alternative names:

Na+; sodium - serum

Normal values:

The normal range is 135 to 145 mEq/L.

Note: mEq/L = milliequivalents per liter

What abnormal results mean:

Greater-than-normal sodium levels (hypernatremia) may indicate:

• Cushing's syndrome (rare)
• dehydration
• diabetes insipidus
• extensive thermal burns
• hyperaldosteronism (very rare)
• osmotic diuresis

Lower-than-normal sodium levels (hyponatremia) may indicate:

• Addison's disease (rare)
• ascites (leakage of fluid into the peritoneum)
• congestive heart failure
• diarrhea
• excessive sweating
• intraluminal bowel loss (ileus or mechanical obstruction)
• ketoacidosis
• kidney disease
• osmotic dilution
• peripheral edema
• pleural effusion
• syndrome of inappropriate antidiuretic hormone secretion
• vomiting or nasogastric aspiration

Additional conditions under which the test may be performed:

• acute adrenal crisis
• diabetic hyperglycemic hyperosmolar coma
• drug-induced hypothyroidism
• hepatorenal syndrome
• hypopituitarism
• hypothyroidism
• hypothyroidism; primary
• hypothyroidism; secondary