preoperative image

Urinalysis

When Are Urine Lab Tests Used?

A healthcare provider may order a urine analysis test for several reasons, such as to check your overall health, to monitor a specific health condition, or to diagnose a medical condition. A urine analysis test involves checking the contents, concentration, and appearance of the urine for any abnormalities. A urine sample is normally evaluated visually, using a dipstick or other lab test, and microscopically.

How Does a Urine Dipstick Test Work?

A urine dipstick test is used in many primary and urgent care clinics to quickly and affordably diagnose everything from urinary tract infections and pregnancy, to drug use. The test uses a plastic strip impregnated with chemicals that change color in the presence of certain substances. For example, a dipstick used to diagnose a urinary tract infection or assess overall health will check for abnormal pH, increased concentration, and the presence of substances ranging from white blood cells and proteins, to glucose and bilirubin. To perform the test, a medical assistant, lab technician, or another provider will simply dip the stick in the urine, wait the designated amount of time, and then compare the colors on the strip to the key on the package or container. Urine spectrometers are also used for this purpose.

How Do I Prepare for a Urine Analysis Test?

Most urine lab tests do not require any special prep or fasting. Depending on your situation, the urine sample may be collected at home, the healthcare provider’s office, or a lab. It is important that you follow your provider’s instructions to ensure the accuracy of the results. The following are the basic steps used for most urine lab tests:

  • Clean the urinary opening. Men should clean the tip of the penis. Women should wipe from front to back while spreading the labia.
  • Start urinating into the toilet and then pass the collection container into the urine stream.
  • The container does not have to be completely full, but you should collect at least 1 to 2 ounces.
  • You can finish urinating into the toilet.
  • Return the sample to the provider.

Depending on the circumstances and the type of test required, the sample may be tested at the clinic using a dipstick or sent to a urinalysis lab for more detailed testing.

What Can Be Detected During Urine Sample Analysis?

A full urine analysis looks for substances in the urine indicative of infection or conditions that impact the body’s ability to remove substances from the body through the urine. Complete urine lab tests typically check the following:

  • Specific gravity, which is the concentration of the urine.
  • The pH of the urine, which is determined by the acid/base balance of the body. A pH that is too high or too low may lead to the development of kidney stones.
  • The color of the urine, which can be affected by foods, medications, blood, or even dehydration.
  • The overall appearance of the urine. Bacteria, blood, mucus, or other contaminants can cause urine to appear cloudy or turbid.
  • White blood cells that may indicate a urinary tract infection.
  • The presence of protein, glucose, ketones, bilirubin, and urobilinogen, which are indicators of liver and kidney function.
  • The presence of nitrites, which may indicate a urinary tract infection.

A full urine analysis test will also include a microscopic examination for the presence of abnormal cells, crystals, mucus, casts, and bacteria.

Reliability

Are Urine Lab Test Results Accurate?

When performed correctly, a urine analysis test can accurately identify the presence of various substances in the urine; however, the method in which the sample is collected, stored, and tested can affect the accuracy of the results.

  • A urine sample analysis may not be accurate if the test strips were exposed to light, excessive heat or cold, moisture, or if the desiccant was removed from the bottle.
  • Reading the strip too soon or allowing the strip to sit too long can alter the results.
  • The chemical used to impregnate the strip can start to deteriorate after the expiration date, which can affect the accuracy of the results.
  • The results may not be accurate if the strip has been contaminated by touching the testing area or by placing it on a contaminated surface.
  • Collecting the urine in a contaminated container may alter the results.
  • It may be difficult to get accurate results after eating certain foods or taking certain medications.
  • Allowing the sample to sit too long at room temperature may alter the results.

Other Tests

When Is a Urine Routine Microscopy Test Used?

A urine routine microscopy may be ordered to diagnose a urinary tract infection, to evaluate for kidney or metabolic disorders, as part of a routine health checkup, as part of pre-surgical clearance, or to detect infections or diseases during pregnancy.

How Does a Kidney Stone Analysis Test Work?

Your healthcare provider may order a kidney stone analysis if you suffer from frequent kidney stones. The test is used to determine the composition of the stone, which can help determine its cause and guide treatment. The test involves filtering the stone from the urine once it has passed so that it can be sent to a lab for testing.

The content provided on the MD Now website is for informational purposes only and is not intended to be a substitute for receiving medical care and treatment from a qualified healthcare provider. Never delay seeking advice, evaluation, and treatment from a medical professional because of what you’ve read on this site, since the information provided may not apply to you or your symptoms.
×