Sodium
Sodium is the main extracellular electrolyte, regulating fluid balance and blood pressure. Levels reflect water balance more than salt intake.
Normal ranges
Adults: 136–145 mmol/L.
Units: mmol/L
Causes of deviations
Low levels:
Excess water intake, diuretics, heart failure, SIADH.
High levels:
Dehydration, diabetes insipidus, excess salt intake.
When to see a doctor
If abnormal — electrolyte imbalance may cause confusion, weakness, seizures.
This information is for educational purposes and does not replace medical advice.
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