What is Urinalysis?

Medical Science, Science
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Reasons for Urinalysis

Urinalysis is a laboratory diagnostic procedure performed when ordered by a doctor or another health care professional which involves testing urine for bacteria, proteins, or other molecules that can provide information about a patient’s health. Urinalysis is performed as part of routine pregnancy check-ups, hospital admission, and pre-surgery examinations, as well as in cases where a urinary tract infection is suspected.

Preparing for a Urinalysis

Preparing for the test is easy. Your doctor may ask you to stop taking medication if it will interfere with the results, but apart from this no other special preparation is required. The process usually involves washing the hands and genital area before collecting some urine in a specimen jar, after which your doctor will send the sample off to a laboratory to be tested.

Information Provided by Urinalysis

A full urinalysis involves a number of different observations and tests. First, a lab technician will examine the color, odor, and appearance of the urine sample, before analyzing the sample in terms of its chemical make-up. In addition, the urine is examined to determine if there are any signs of bacterial infection. If infection is noted, a sample of the urine is cultured to determine what type of bacteria is causing the infection.

  • Color: Normal urine color depends on its concentration: highly concentrated urine is an amber-orange color, while dilute urine is pale yellow. Bleeding from the kidneys, bladder, or urethra stains urine red, while cloudy urine can indicate a bacterial infection.

  • Odor: Certain odors can indicate problems such as a foul-smelling odor that indicates a urinary tract infection, or a sweet smell that may indicate diabetes.

  • PH: When the kidneys are not functioning normally the PH of urine may change.

  • Specific Gravity: This term refers to how concentrated the urine is. If urine is highly dilute it may indicate kidney disease, while very concentrated urine is a symptom of dehydration.

  • Protein: Healthy urine contains very little protein. When protein is found in the urine it usually indicates kidney damage or disease. Protein in the urine can also indicate preeclampsia in pregnant women.

  • Crystals**:** The development of a kidney stone is often preceded by the presence of mineral crystals in urine.

  • Casts: These clumps of cells and protein that form in the kidneys may indicate kidney disease or failure if found in the urine. They can also appear after strenuous exercise.

  • Bilirubin or Urobilinogen: When found in the urine, these pigments may indicate liver damage or disease.

Resources

Laboratory Corporation of America: Patient Information on Urinalysis