| Inbound Relationships | Type | Active | Source | Characteristic | Refinability | Group | 
| Sodium measurement, serum | Is a | False | Sodium measurement | Inferred relationship | Existential restriction modifier |  | 
| Sodium measurement, urine | Is a | False | Sodium measurement | Inferred relationship | Existential restriction modifier |  | 
| Measurement of fractional excretion of sodium | Is a | True | Sodium measurement | Inferred relationship | Existential restriction modifier |  | 
| Fluid sample sodium measurement | Is a | True | Sodium measurement | Inferred relationship | Existential restriction modifier |  | 
| Sweat sodium measurement | Is a | False | Sodium measurement | Inferred relationship | Existential restriction modifier |  | 
| Blood sodium measurement | Is a | True | Sodium measurement | Inferred relationship | Existential restriction modifier |  | 
| Plasma sodium measurement | Is a | False | Sodium measurement | Inferred relationship | Existential restriction modifier |  | 
| Potassium/sodium ratio measurement | Is a | True | Sodium measurement | Inferred relationship | Existential restriction modifier |  | 
| Finding of sodium level | Interprets | True | Sodium measurement | Inferred relationship | Existential restriction modifier | 1 | 
| Sodium in sample | Interprets | False | Sodium measurement | Inferred relationship | Existential restriction modifier | 1 | 
| Measurement of urea, sodium, potassium, chloride, bicarbonate and creatinine | Is a | True | Sodium measurement | Inferred relationship | Existential restriction modifier |  | 
| Measurement of urea, sodium, potassium, chloride, bicarbonate and glucose | Is a | True | Sodium measurement | Inferred relationship | Existential restriction modifier |  | 
| Sodium output measurement | Is a | True | Sodium measurement | Inferred relationship | Existential restriction modifier |  |