Skip to main content


urinalysis (yŏŏr´ənăl´ĬsĬs), clinical examination of urine for the purpose of medical diagnosis. Urine is initially examined for such characteristics as color, odor, and specific gravity. It is routinely tested for acidity, as indicated by its pH reading, and screened for sugar, ketone bodies, proteins, and bile content. Benedict's solution, for example, may be used to test for simple sugars, a high level of which is a possible indicator of diabetes mellitus. Ketone bodies, e.g., acetone and acetoacetic acid, in the urine indicate the substitution of fats for sugar in the energy cycle and are another indication of diabetes mellitus. Abnormal levels of protein may be signs of kidney disease. A high concentration of bile in the urine is a sign of liver malfunction or blockage of the bile duct. Urine is examined microscopically to determine blood count. High levels of erythrocytes, or red blood cells, and leukocytes, or white blood cells, may be a result of bleeding and infection, respectively, in the urinary tract. Casts, crystals, and other substances, whose origins may be ascertained by determining their chemical structures, can be observed microscopically. Additional studies are performed when specific malfunctions are suspected. Clearance tests, for instance, will determine the ability of the kidneys to remove waste substances from the blood plasma per unit of time. The urine of patients with melanotic cancer will often contain melanin, a skin pigment. A diagnosis of drug addiction may be confirmed by the presence of specific chemical substances in the urine. Urinalysis is also employed to test for pregnancy. Pregnant women secrete high levels of gonadotrophic, or ovary-regulating, hormones from the placenta. A reagent containing gonadotrophic hormones is mixed with a sample of urine from the patient, and gonadotrophic antigens are added to it. Failure of the antigens to clump, or agglutinate, is positive evidence of pregnancy.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"urinalysis." The Columbia Encyclopedia, 6th ed.. . 20 Jul. 2018 <>.

"urinalysis." The Columbia Encyclopedia, 6th ed.. . (July 20, 2018).

"urinalysis." The Columbia Encyclopedia, 6th ed.. . Retrieved July 20, 2018 from

Learn more about citation styles

Citation styles gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, cannot guarantee each citation it generates. Therefore, it’s best to use citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

The Chicago Manual of Style

American Psychological Association

  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.