Specific Gravity

Specific gravity is an indication of the amount of solid particles dissolved in a urine sample. We can determine a quantitative level of specific gravity in a urine sample. A normal urine sample has a specific gravity of greater than or equal to 1.003.

If a urine sample has a creatinine value less than 20 mg/dLand a specific gravity less than 1.003, then the sample is considered dilute and will be reported as such. This dilution can come from either drinking large volumes of liquid before providing a urine sample, or pouring something into the urine cup at the time of collection. Either way, the sample is considered dilute, and may not provide a proper evaluation of drug use by the donor/patient. We advise re-testing if a sample appears to have been diluted.