| Inbound Relationships | Type | Active | Source | Characteristic | Refinability | Group | 
| Sodium measurement, serum | Is a | False | Sodium measurement | Inferred relationship | Some |  | 
| Sodium measurement, urine | Is a | False | Sodium measurement | Inferred relationship | Some |  | 
| Measurement of fractional excretion of sodium | Is a | True | Sodium measurement | Inferred relationship | Some |  | 
| Fluid sample sodium measurement | Is a | True | Sodium measurement | Inferred relationship | Some |  | 
| Sweat sodium measurement | Is a | False | Sodium measurement | Inferred relationship | Some |  | 
| Blood sodium measurement (procedure) | Is a | True | Sodium measurement | Inferred relationship | Some |  | 
| Plasma sodium measurement (procedure) | Is a | False | Sodium measurement | Inferred relationship | Some |  | 
| Potassium/sodium ratio measurement | Is a | True | Sodium measurement | Inferred relationship | Some |  | 
| Sodium level - finding | Interprets | True | Sodium measurement | Inferred relationship | Some | 1 | 
| concentratie van natrium in monster (bevinding) | Interprets | False | Sodium measurement | Inferred relationship | Some | 1 | 
| Measurement of urea, sodium, potassium, chloride, bicarbonate and creatinine (procedure) | Is a | True | Sodium measurement | Inferred relationship | Some |  | 
| Measurement of urea, sodium, potassium, chloride, bicarbonate and glucose (procedure) | Is a | True | Sodium measurement | Inferred relationship | Some |  | 
| Hyponatremia | Interprets | True | Sodium measurement | Inferred relationship | Some | 1 | 
| Hyponatremia with excess extracellular fluid volume | Interprets | True | Sodium measurement | Inferred relationship | Some | 1 | 
| Water intoxication syndrome | Interprets | True | Sodium measurement | Inferred relationship | Some | 2 | 
| Hyponatremia with normal extracellular fluid volume | Interprets | True | Sodium measurement | Inferred relationship | Some | 1 | 
| Cerebral hyponatremia | Interprets | True | Sodium measurement | Inferred relationship | Some | 3 | 
| Chronic hyponatremia | Interprets | True | Sodium measurement | Inferred relationship | Some | 2 | 
| Hyponatremia with decreased serum osmolality | Interprets | True | Sodium measurement | Inferred relationship | Some | 1 | 
| Pseudohyponatraemia | Interprets | True | Sodium measurement | Inferred relationship | Some | 1 | 
| Transurethral resection of prostate (TURP) syndrome | Interprets | True | Sodium measurement | Inferred relationship | Some | 3 | 
| Dilutional hyponatremia | Interprets | True | Sodium measurement | Inferred relationship | Some | 1 | 
| Acute hyponatremia | Interprets | True | Sodium measurement | Inferred relationship | Some | 1 | 
| Transitory neonatal hyponatraemia | Interprets | True | Sodium measurement | Inferred relationship | Some | 3 | 
| Paraneoplastic hyponatremia (disorder) | Interprets | True | Sodium measurement | Inferred relationship | Some | 1 | 
| Drug-induced hyponatremia | Interprets | True | Sodium measurement | Inferred relationship | Some | 2 | 
| Hyponatremia with extracellular fluid depletion | Interprets | True | Sodium measurement | Inferred relationship | Some | 2 |