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.
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:
- 24-hour urine collection
- Clean catch urine specimen
The sample is sent to a lab, where it examined for the following:
1) Physical color and appearance. (What does the urine look like to the naked eye? Is it clear or cloudy? Is it pale or dark yellow or another color?)
2) Specific gravity. The urine specific gravity test reveals how concentrated or dilute the urine is.
3) Microscopic appearance. 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.
4) 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, such as protein, glucose, or ketones.
Reference: National Library of Medicine.