Table 1.
Differential diagnosis of hyponatremia
| Hyponatremia | ||||||
|---|---|---|---|---|---|---|
| |
Hypervolemic |
Euvolemic |
Hypovolemic |
|||
|
TBW |
++ |
+ |
+ |
+ |
- |
_ |
|
TBNa |
+ |
N |
N |
N |
- |
- |
|
Urine Na |
- |
+ |
N/+ |
- |
- |
- |
|
Urine Osm |
+ |
+ |
+ |
- |
+ |
+ |
|
Edema |
+ |
- |
- |
- |
- |
- |
|
BP |
- |
N |
N |
N |
- |
- |
|
Diuresis |
-/N |
-/N |
N |
+ |
_ |
+ |
|
Possible diagnoses |
CHF |
SIAD |
Drugs |
Primary Polydipsia |
NON renal Losses: |
Renal Losses: |
| |
Cirrhosis |
|
Nausea |
|
|
Diuretics |
| |
Nephrotic Syn. |
|
Addison |
|
Vomiting |
C/RSWS |
| |
|
|
|
|
Diarrhea |
|
| Sweating | ||||||
TBW: Total Body Water, TBNa: Total Body Sodium, BP: Blood Pressure, CHF: Chronic Heart Failure,
SIAD: Syndrome of Inappropriate Antidiuresis, C/RSWS: Cerebral Renal Salt Wasting Syndrome. N: Normal, +:elevated, -: reduced.