AsseyMethod: ISE
Abbrevation: Sodium - Na
Sector: Biochemistry
SampleType: S
S.Vol: -
Transport: at 2-8˚c, -20˚c
Storage: 1 day at 2-8˚c,for 1 month at -20˚c
Test Name: Sodium
Normal Range: 130-145

This test is related to
Why get tested?

To determine if concentrations of sodium are normal, too high (hypernatraemia) or too low (hyponatraemia) as part of diagnosis and monitoring the treatment of related illnesses

When to get tested?

In routine medical examination to investigate causes of dehydration, oedema, problems with blood pressure, or non-specific symptoms; as part of routine laboratory evaluations, or to monitor certain long-term conditions, like high or low blood pressure

Sample required?

A blood sample is taken by needle from the arm. In some cases, a random urine sample or a 24 hour collection may be required.

Test preparation needed?


What is being tested?

This test measures the concentration of sodium in blood or urine. Sodium is an electrolyte present in all body fluids, and is vital to normal body function including nerve and muscle function. Your body tries to keep your blood sodium within a very small concentration range; it does so by:

  • producing hormones that can increase (such as natriuretic peptides) or decrease (such as aldosterone) sodium losses in urine
  • producing a hormone that prevents water losses (antidiuretic hormone [ADH], sometimes called vasopressin)
  • controlling thirst (even a 1% increase in blood sodium concentration will make you thirsty and cause you to drink water, returning your sodium towards normal.)

These controls regulate the amount of water and sodium in the body and control blood pressure by keeping the amount of water available. An abnormal blood sodium concentration is usually due to some problem with one of these systems. When the concentration of sodium in the blood changes, the water content in your body changes. These changes can be associated with dehydration (too little fluid) or oedema (too much fluid, often resulting in swelling in the legs) and changes in blood pressure. In some people, too much sodium from salt in the diet can contribute to high blood pressure.