Urine specific gravity is a laboratory test that measures the concentration of all chemical particles in the urine.
The test requires a clean-catch urine sample. For information on how to collect this urine sample, see: Clean-catch urine culture
Your health care provider will instruct you, if necessary, to discontinue drugs that may interfere with the test. Drugs that can increase specific gravity measurements include dextran and sucrose. Receiving intravenous dye (contrast medium) for an x-ray exam up to 3 days before the test can also interfere with results.
Eat a normal, balanced diet for several days before the test.
The test involves only normal urination, and there is no discomfort.
This test helps evaluate your body's water balance and urine concentration.
Normal values are between 1.000 to 1.030.
The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
Increased urine specific gravity may be due to:
Decreased urine specific gravity may be due to:
Additional conditions under which the test may be performed:
Osmolality is a more specific test for urine concentration. However, the specific gravity measurement is easier and more convenient and usually part of a routine urinalysis. It frequently makes the osmolality measurement unnecessary.
Landry DW, Bazari H. Approach to the patient with renal disease. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 116.