Kidney & Electrolytes
Sodium
Kidney & Electrolytes
Essential electrolyte. Imbalances affect blood pressure and fluid balance.
VAT-exempt medical service
Sodium is present in all body fluids, with the highest concentrations in the blood. It works with potassium and calcium to maintain proper cell function and fluid balance. The body tightly regulates sodium through hormonal mechanisms and the thirst response. A sodium blood test reveals whether these regulatory systems are working as they should.
Testing sodium is essential for managing health risks related to diet and lifestyle. A high intake of processed foods, sodium, and alcohol can disrupt balance. Regular testing monitors changes as you adjust your lifestyle, take supplements or medications, or manage conditions such as dehydration, high blood pressure, or oedema. Athletes should also monitor sodium for optimal performance.
What a high value can mean
High sodium (hypernatraemia) is nearly always caused by dehydration -- not replacing lost water sufficiently. Rarely, it can result from excessive salt intake, Cushing syndrome, or diabetes insipidus. Certain medications, including corticosteroids, anabolic steroids, and oral contraceptives, can also raise sodium.
What a low value can mean
Low sodium (hyponatraemia) is more common and can result from excessive sweating, diarrhoea, diuretic use, endurance exercise, or excess water intake. Serious underlying conditions include heart failure, liver cirrhosis, kidney damage, and adrenal insufficiency. It is more prevalent in the elderly.
No preparation is needed. Bring valid ID to your appointment.
Order your test
Choose your test and pay online. Your lab referral is created straight away.
Give your sample
Visit any of our partner sampling locations. No appointment needed at most of them.
The lab analyses it
Your sample is analysed at an accredited Swedish laboratory.
Get your results
Your values appear in your account with reference ranges and an explanation of each marker.
Yes. Excessive water intake, especially during endurance sports, can dilute sodium in the blood and cause a condition called hyponatraemia, which can be serious.
Yes. ACE inhibitors, diuretics, and antidepressants can lower sodium, while corticosteroids and oral contraceptives can raise it. Always inform your doctor about your medications.
Sodium helps regulate fluid volume in the blood. Too much sodium draws more water into the bloodstream, increasing blood volume and raising blood pressure over time.