Why get tested?
To determine whether your sodium concentration is within normal limits and to help evaluate electrolyte balance and kidney function; to monitor chronic or acute hypernatremia or hyponatremia

When to get tested?
If you are experiencing dehydration or edema; also to monitor certain chronic conditions, like high or low blood pressure

Sample required?
A blood sample drawn from a vein in the arm or, in some cases, a urine sample