| Pseudohyponatremia |
Plasma’s lipid, protein, and glucose content are increased, whereas the sodium content of plasma water is within the normal range (135–145 mmol/L) |
| Euvolemic hyponatremia |
Total body volume increased, whereas total sodium is normal (135–145 mmol/L) |
| Hypovolemic hyponatremia |
Total body volume decreased and serum sodium < 135 mmol/L |
| Hypervolemic hyponatremia |
Total body volume increased and serum sodium < 135 mmol/L |
| Biochemical hyponatremia |
Serum sodium ranges from 129 to 134.9 mmol/L |
| Clinically significant hyponatremia |
Serum sodium < 129 mmol/L |
