Plasma osmolality laboratory test

A plasma osmolality test measures the concentration of particles like salts, glucose, and urea in your blood. It indicates how well your body maintains fluid balance and can help diagnose dehydration, overhydration, or certain health conditions affecting fluid and electrolyte balance. The test results are expressed in units called milliosmoles per kilogram (mOsm/kg). Normal levels typically range from about 275 to 295 mOsm/kg. Abnormal results can alert your healthcare provider to underlying issues that may require further investigation or treatment.