Urine sodium
What this test measures
The concentration of sodium in a urine sample. It reflects salt intake and how the kidney is handling salt and water at that moment, so it has no fixed range.
Why doctors request it
Hospital doctors use it when blood sodium is abnormal or when checking salt intake in kidney and blood pressure clinics.
What commonly pushes it up
- A high salt diet
- Some water tablets as a class
- Some hormone conditions
What commonly pushes it down
- A low salt diet
- Dehydration or blood loss, where the kidney holds on to salt
- Heart or liver failure with fluid retention
Everyday reasons for a value outside the range
- It is entirely a reflection of intake and the moment, so single values have no typical range
- Spot and 24-hour values are different measures
About the sample
Read only alongside blood tests taken at the same time.
Upload a photo or PDF and see every line against the range your lab printed, explained in plain English. First report free.
Read my report freeThis is an educational summary of results you uploaded. It is not medical advice, a diagnosis or a treatment plan, and it does not replace the doctor who requested the test. If you are worried, or a result is marked outside range, discuss it with your doctor. Written and reviewed by a UK consultant physician. Reference ranges vary between laboratories.