A sodium blood test measures how much sodium (salt) is in your blood.
Sodium helps control:
Fluid balance
Blood pressure
Nerve and muscle function
This test is often part of a Basic or Comprehensive Metabolic Panel.
This test looks at the level of sodium in your bloodstream.
Sodium levels are closely linked to:
Hydration
Kidney function
Hormones that regulate fluid
Even small changes can reflect changes in body water.
Normal sodium ranges vary slightly by lab.
Your lab report will show:
Your sodium level
The lab’s reference range
Mild changes are very common.
Low sodium (hyponatremia) may be caused by:
Overhydration
Certain medications
Hormone changes
Illness or infection
Many mild cases cause no symptoms.
High sodium (hypernatremia) may be linked to:
Dehydration
Not drinking enough fluids
Fever or illness
Certain medications
Hydration often plays a key role.
Sodium levels can change due to:
Dehydration or excess fluids
Vomiting or diarrhea
Medications
Lab timing
One result alone rarely means something serious.
Doctors may repeat this test if:
Levels are clearly outside normal
Symptoms are present
They are monitoring hydration or kidney function
Trends over time matter more than one test.
Mild sodium imbalances are very common and often correct with simple changes.
Doctors interpret sodium together with other electrolytes and symptoms.
Sodium helps regulate fluid balance in the body.
Most abnormal results are temporary and explainable, especially during illness or dehydration.
You may want to read:
Potassium Blood Test Explained
Chloride Blood Test Explained
Comprehensive Metabolic Panel (CMP) Explained
You can also use the navigation bar above to explore other blood test results.
This information is for educational purposes only and is not medical advice. Always talk with a healthcare professional about your results.