Insight into your sodiumlevel.
Sodium is the most important electrolyte outside the cells and helps determine the fluid balance. A test gives insight into the water and salt balance in your blood.
Also known as: Na, salt, electrolytes
Interpreted by BIG-registered doctors
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Background
What is sodium?
Sodium is the most important electrolyte in the fluid outside the cells. It helps determine how much water the body retains and where that water is located. Sodium also plays a role in the signal conduction of nerves and muscles. The kidneys regulate sodium balance precisely, together with hormones that steer the fluid balance.
A common misconception is that the sodium level in the blood shows how much salt you eat. That is not correct. The value is mainly a measure of the ratio between water and salt in the body, the water and salt balance. With healthy kidney function the body keeps that ratio stable, even when salt intake varies. Abnormalities are therefore seen more often with dehydration, with excessive drinking, with certain medicines such as diuretics, and with hormonal causes.
In brief
Outside the cells
The main electrolyte in the fluid around the cells
Fluid balance
Helps determine how much water the body retains
Not your salt intake
The value says more about the water and salt balance
Kidneys and hormones
Together they regulate sodium balance precisely
Common reasons to test
When can insight into your Sodium be valuable?
Below are some situations in which measuring Sodium can provide insight.
Insight into your water and salt balance
Sodium is a common first step in assessing the balance between water and salt.
With diuretic use
Diuretics influence the excretion of water and salt via the kidneys. Sodium is therefore monitored more often with this medication.
With high blood pressure
The water and salt balance is linked to blood pressure. Sodium is therefore often viewed together with the kidney values.
With dehydration or significant fluid loss
Heavy sweating, vomiting or diarrhoea affect the fluid balance. A test gives insight into the consequences.
For endurance athletes
During long exertion you lose fluid and salt through sweat, and you drink a lot. Both influence the sodium level.
Tracking a value over time
For electrolytes the development over time is often more informative than a single measurement. Re-testing makes a change visible.
What your result means
How do we read your Sodium level?
Sodium is measured in millimoles per litre (mmol/L). The laboratory states the reference values that apply there alongside your result. Important: the value says more about the ratio between water and salt than about how much salt you eat.
A low value
A low sodium level usually indicates that there is relatively too much water in the body. This is seen with excessive drinking, with the use of diuretics, with certain hormonal causes, and with heart, liver or kidney conditions. A single measurement is not a diagnosis. Our doctor explains what your value means and whether re-testing or follow-up via your GP is customary.
A normal value
A sodium level within the laboratory's reference values gives a reassuring picture of the water and salt balance at this moment. It remains a snapshot: the balance can differ from day to day, for example due to your fluid intake.
An elevated value
An elevated sodium level usually indicates that there is relatively too little water in the body, for example due to dehydration, insufficient drinking or significant fluid loss. Hormonal causes can also play a role. Our doctor provides explanation and context with your result.
How we interpret your result
Our doctors interpret your sodium level against the laboratory's reference values and your personal context, such as fluid intake, lifestyle, medication use and any known conditions.
Related tests
Often combined with Sodium.
A single marker gives one perspective. For a broader picture you can combine Sodium with a theme package or related markers.
Frequently asked questions
Everything you want to know
Do I need to fast for a sodium test?
No, you do not need to fast for sodium. Do drink as you normally would, as both dehydration and excessive drinking can influence the value.
Does my sodium level say anything about how much salt I eat?
No. The sodium level in the blood is mainly a measure of the ratio between water and salt in the body. With healthy kidney function that ratio stays stable, even when your salt intake varies. A blood value is not the appropriate measurement for insight into your salt intake.
What is the difference between sodium and potassium?
Sodium is found mainly in the fluid outside the cells and helps determine the fluid balance. Potassium is found mainly inside the cells and plays a role in the signal conduction of muscles and the heart. They are often measured together because the kidneys regulate both.
Can drinking a lot of water influence my sodium level?
Yes. If you drink a very large amount of water in a short time, this dilutes the blood and the sodium level can fall. Therefore drink as you normally would before the draw, so your result is easier to interpret.
Which medicines influence the sodium level?
Diuretics are the best known. Certain blood pressure medicines, antidepressants and anti-epileptics can also influence the sodium level. Please mention your medication with your result, so the doctor can take it into account.
Is a single abnormal value immediately worrying?
Not necessarily. A single measurement is not a diagnosis. Fluid intake, fluid loss and medication use can temporarily shift the value. The doctor looks at your context and advises whether re-testing is useful.
How often should I have sodium measured?
A single measurement is enough for initial insight. With the use of diuretics, with a previously abnormal value, or with a known kidney or heart condition, periodic re-testing is customary.
What do I do with my result?
You receive a PDF report with your value and personal explanation. What you do with it, such as discussing it with your GP, remains entirely your choice.
Ready for insight into your sodium level?
For €49 you receive your sodium level including personal explanation from a doctor, typically within a few working days. No referral required.
Order Sodium for €49 →Want to test multiple markers at once?
Combine Sodium with other markers via Bloodworks Select. Blood draw costs are waived from €225.
49,-
All-in, blood draw included