What it measures
Urine osmolality measures how concentrated a urine sample is, by counting the particles dissolved in it, such as salts and urea. It shows how well the kidneys are concentrating or diluting urine.
Why people test it
- Measured with blood sodium to help find the cause of a low sodium level.
- Checked when someone is very thirsty or passes large amounts of urine.
- Used with blood osmolality to see how the body is handling water.
Typical range
Ranges vary between labs, with the method used, age and sex, and your report shows the lab's own range. There is no single normal value, as the result changes with how much someone has drunk and is read alongside blood sodium and blood osmolality.
Finger-prick or vein?
A urine sample, not blood. Offered as a kit only.