Also Known As :

Urine Test, Urine Analysis, UA

Formal Name :

Urinalysis

Sample Required :

One to two ounces of urine—a sufficient sample is required for accurate results; sometimes you may be directed to collect a sample using a "clean-catch" technique: women should spread the labia of the vagina and clean from front to back; men should wipe the tip of the penis. Start to urinate, let some urine fall into the toilet, then collect one to two ounces of urine in the container provided, then void the rest into the toilet.

Test Preparation Needed :

None

What is being tested?

A urinalysis is a group of physical, chemical, and microscopic tests. The tests detect and/or measure several substances in the urine, such as by-products of normal and abnormal metabolism, cells, cellular fragments, and bacteria.

Overview

Urine is produced by the kidneys, two fist-sized organs located on either side of the spine at the bottom of the ribcage. The kidneys 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 eliminated in the urine, traveling from the kidneys through ureters to the bladder and then through the urethra and out of the body. Urine is generally yellow and relatively clear, but each time a person urinates, the colour, quantity, concentration, and content of the urine will be slightly different because of varying constituents.

Many disorders may be detected in their early stages by identifying substances that are not normally present in the urine and/or by measuring abnormal levels of certain substances. Some examples include glucose, protein, bilirubin, red blood cells, white blood cells, crystals, and bacteria. They may be present because:

• There is an elevated level of the substance in the blood and the body responds by trying to eliminate the excess in the urine.
• Kidney disease is present.
• There is a urinary tract infection present, as in the case of bacteria and white blood cells.

Consists of:

A complete urinalysis consists of three distinct testing phases:

• Visual examination, which evaluates the urine's colour and clarity
• Chemical examination, which tests chemically for about 9 substances that provide valuable information about health and disease and determines the concentration of the urine.
• Microscopic examination, which identifies and counts the type of cells, casts, crystals, and other components such as bacteria and mucus that can be present in urine.
A microscopic examination is typically performed when there is an abnormal finding on the visual or chemical examination, or if a healthcare practitioner specifically orders it.
Abnormal findings on a urinalysis may prompt repeat testing to see if the results are still abnormal and/or may be followed by additional urine and blood tests to help establish a diagnosis.

Ever wonder what happens to your blood sample once it's been collected? It's sent "to the lab" for analysis, but what does that entail? This article will take you on a tour as a blood sample is processed.
In the laboratory, trained laboratorians use various methods to analyze your sample as determined by what types of tests you need performed. The Who's Who in the Lab article introduces you to these lab personnel.
For every test, there is an appropriate sample that provides the best information for that test.

Test Process

How is the sample collected for testing?

One to two ounces of urine is collected in a clean container. A sufficient sample is required for accurate results.
Urine for a urinalysis can be collected at any time. In some cases, a first morning sample may be requested because it is more concentrated and more likely to detect abnormalities.
Sometimes, you may be asked to collect a "clean-catch" urine sample. For this, it is important to clean the genital area before collecting the urine. Bacteria and cells from the surrounding skin can contaminate the sample and interfere with the interpretation of test results. With women, menstrual blood and vaginal secretions can also be a source of contamination. Women should spread the labia of the vagina and clean from front to back; men should wipe the tip of the penis. Start to urinate, let some urine fall into the toilet, then collect one to two ounces of urine in the container provided, then void the rest into the toilet.
A urine sample will only be useful for a urinalysis if taken to the healthcare provider's office 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 or a preservative may be added.

How are the test results used?

The urinalysis is a set of screening tests that can detect some common diseases. It may be used to screen for and/or help diagnose conditions such as a urinary tract infection, kidney disorders, liver problems, diabetes or other metabolic conditions, to name a few.
A urinalysis is comprised of several chemical, microscopic and visual examinations used to detect cells, cell fragments and substances such as crystals or casts in the urine associated with the various conditions listed above. It can detect abnormalities that might require follow-up investigation and additional testing. Often, substances such as protein or glucose will begin to appear in the urine before people are aware that they may have a problem.
In people diagnosed with diseases or conditions, such as kidney disease or diabetes, the urinalysis may be used in conjunction with other tests, such as urine albumin, to follow treatment.
There are many factors that can affect or interfere with the tests that comprise a urinalysis. If instructed to do so, it is important to follow the directions carefully for a "clean-catch" sample. Give a complete history to your healthcare practitioner, including any prescribed or over-the-counter medications or supplements you may be taking. If you are a woman, be sure to tell your healthcare practitioner whether you are menstruating.

Is the time of day a factor when collecting a urine sample?

Because this is a general screening test, time of collection is usually not important, although a first morning void may be preferred because it is more concentrated. However, if your healthcare provider is looking for a specific finding, you may be asked to collect a sample at a specific time.