Urinalysis is the physical, chemical, and microscopic examination of urine. It involves a number of tests to detect and measure various compounds that pass through the urine.
How the Test is Performed
A urine sample is needed. Your health care provider will tell you what type of urine sample is needed. For information on how to collect a urine sample, see:
The urine sample is examined under a microscope to look at cells, urine crystals, mucus, and other substances in the sample, and to identify any bacteria or other germs that might be present.
Chemical appearance:
A special stick ("dipstick") tests for various substances in the urine. The stick contains little pads of chemicals that change color when they come in contact with the substances of interest.
How to Prepare for the Test
Certain medicines change the color of urine, but this is not a sign of disease. Your doctor may tell you to stop taking any medicines that can affect test results.
Medicines that can change your urine color include:
Chloroquine
Iron supplements
Levodopa
Nitrofurantoin
Phenazopyridine
Phenothiazines
Phenytoin
Riboflavin
Triamterene
How the Test Will Feel
The test involves only normal urination, and there is no discomfort.
Why the Test is Performed
A urinalysis may be done:
As part of a routine medical exam to screen for early signs of disease
If you have signs of diabetes or kidney disease, or to monitor you if you are being treated for these conditions
Considerations
Normal urine may vary in color from almost colorless to dark yellow. Some foods (like beets and blackberries) may turn the urine a red color.
Usually, glucose, ketones, protein, and bilirubin are not detectable in urine. The following are not normally found in urine:
Hemoglobin
Nitrites
Red blood cells
White blood cells
Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
For specific results, see the individual test article:
Considerations
If a home test is used, the person reading the results must be able to distinguish between different colors, since the results are interpreted using a color chart.
Alternative Names
Urine appearance and color; Routine urine test
References
McPherson RA, Ben-Ezra J, Zhao S. Basic examination of urine. In: McPherson RA, Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods
. 21st ed. Philadelphia, Pa: W.B. Saunders Company; 2006:chap 27.
Update Date: 2/1/2011
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
