Urinalysis

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Also known as: Urine test; Urine analysis
Formal name: Urinalysis

At a Glance

Why Get Tested?

To look for metabolic and kidney disorders and for urinary tract infections

When to Get Tested?

On admission to a hospital; preparation for surgery; as part of a medical examination; or when evaluating a new pregnancy. It may be done if you have tummy or back pain, frequent or painful urination, or blood in the urine

Sample Required?

Sample of urine (20-50 mls) in a sterile container; the first urine passed in the morning is the most valuable

The Test Sample

What is being tested?

This test identifies and measures some of the by-products of normal and abnormal metabolism, cells, cell fragments, and bacteria in urine. Urine is produced by the kidneys, which filter wastes out of the blood, help regulate the amount of water in the body, and conserve proteins, electrolytes, and other compounds that the body can reuse. Anything that is not needed is excreted in the urine.

Several diseases can be diagnosed in their early stages by detecting abnormalities in the urine. Abnormally high levels of glucose, protein, bilirubin, red blood cells, white blood cells, crystals, and bacteria can indicate disease. They may be present because: 1) There are elevated concentrations in the blood which spill over into urine, 2) Kidney disease has made the kidneys less effective at filtering or, 3) An infection has put bacteria and white blood cells into the urine .

A complete urinalysis consists of three distinct testing phases:

  • Visual examination, which evaluates the urine's colour, clarity, and concentration;
  • Chemical examination, which tests chemically for a number of substances that provide valuable information about health and disease; and
  • Microscopic examination, which identifies and counts the type of cells, casts, crystals, and other components (bacteria, mucous ) that can be present in urine.
  • Today, a routine urinalysis consists of the visual and the chemical examinations. Your urine may be examined under a microscope if there is an abnormal finding in one of the first two phases listed above or if your doctor specifically requests it.

    How is the sample collected for testing?

    Urine for urinalysis can be collected at any time. The first morning sample is the most valuable because it is more concentrated and more likely to yield abnormal results. Because of the potential (particularly in women) to contaminate urine with bacteria and cells from the surrounding skin, it is important to first clean the genitalia. Men should wipe the tip of the penis; women should spread the labia of the vagina and clean from front to back. As you start to urinate, let some urine fall into the toilet, then collect a sample of urine in the container provided.

    A sample will only be useful for urinalysis if taken to the doctor’s surgery or laboratory for processing within a short period of time. If it will be longer than an hour between collection and transport time, then the urine should be refrigerated.

    NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

    Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

    The Test

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    NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.