Metabolic panel
Sodium
Sodium is the main salt in the fluid around your cells, and its level mostly reflects the balance between salt and water in the body rather than how much salt you eat.
Typical adult reference range
Roughly 135 to 145 · mmol/L
Ranges vary between laboratories and by age, sex and method. Always read your own result against the range printed on your own report.
What a high result can mean
A high sodium usually means relative water loss, from not drinking enough, from fluid loss, or occasionally from hormonal causes. It is more common in older adults and in anyone whose thirst signalling is blunted.
What a low result can mean
A low sodium is one of the most common abnormalities in routine bloods. Causes include some medicines, particularly diuretics and certain antidepressants, heart, liver and kidney conditions, hormonal problems, and drinking large volumes of water. Falling quickly matters more than being mildly low for a long time.
What commonly affects this result
Hydration, diuretics, antidepressants, recent endurance exercise, and intravenous fluids.
Questions worth asking your doctor
- Has my sodium changed quickly or has it been low for a while?
- Could one of my medicines be causing this?
- How much should I be drinking, given this result?
See what your own results say
Upload your blood test and get a plain English summary of every value on it, with the questions worth raising at your next appointment.
Analyse my resultsThis page explains what a test measures. It is general information, not medical advice, and it cannot tell you what your own result means. Reference ranges differ between laboratories, and results are only meaningful alongside your history, your symptoms and your other results. Always discuss your results with your doctor.