Creatinine levels are not the only measurement taken to determine if a sample has been diluted or not.  Another parameter of the drug test would be the specific gravity of the urine sample. A urine sample must have a specific gravity of 1.003 or less to be considered a diluted sample. The test for specific gravity in the urine is the procedure upon which the concentrations of any and all chemicals in the urine are measured.  There are certain drugs that can interfere with an accurate measurement of specific gravity such as sucrose or dextran.  Also, if you are to receive an intravenous dye for an x-ray exam, this may also interfere with the measurement of specific gravity in the urine sample.

The average specific gravity reading in a urine sample will be between 1.000 and 1.030. There are a few reasons why the specific gravity may be above the average.  One of the simplest explanations is dehydration.  This makes sense because a diluted sample would measure below the average due to overloading the system with fluids so conversely a lack of fluids would cause an increased specific gravity reading.  If you have severe diarrhea then this may lead to dehydration which would increase the specific gravity of the urine sample.  Decreased blood flow to the kidneys may also be a cause for high specific gravity as well as medical conditions like renal arterial stenosis and Addison’s disease.  Kidney function is the key to determining the specific gravity results in a routine urinalysis as this indicates problems with the sample.

(To Be Continued)