Hyponatremia

(Exclude conditions with normal osmolality - i.e. hyperlipidemia, hyperproteinemia,
other solutes such as hyperglycemia, mannitol, alcohols, etc.)

  Renal losses
(Diuretics,
Addison's
interstitial
disease)		 Extrarenal
(GI, sweat,
3rd space)		 SIADH
hypothyroid		 Nephrotic
syndrome,
CHF,
cirrhosis		 Renal
failure		 Water
intoxication
Volume status Mildly
normal
Urine Na (mEq/L) >20 <10 >20 <10 >20 >20
Treatment* Isotonic
Saline		 Isotonic
Saline		 H2O
restriction		 H2O
restriction		 H2O
restriction		 H2O
restriction
Urine osmolality variable Normal or
 Normal or
 Normal or
 Variable

*If Na <120 mEq/L and neurologic signs (i.e., seizures, confusion, etc.) are present, treat with
3% NaCl ± furosemide 40-80 mg IV with a goal of raising the serum Na to approximately
125 mEq/L over approximately 8 hrs.