Urinalysis

Overview & Description

A urinalysis is an analysis of the urine. A doctor does a series of physical, microscopic, and chemical tests on a sample of urine. The tests can screen for kidney disease and infections of the urinary tract. It can also help diagnose diseases that produce abnormal breakdown products called metabolites that are passed from the body in the urine.

How is the test performed?

First, the person washes around the urethra, the tube that passes urine out of the body. This prevents contamination of the sample. Next, the person needs to collect a urine sample in midstream, that is, not at the beginning and not at the end. This is referred to as a clean-catch urine sample.
The person should follow these steps to get the sample. First, the person starts urinating into the toilet. Then, he or she catches a sample of urine in a container. Then the person may finish urinating in the toilet. The person then covers the container and gives it to the doctor.
The sample is sent to a laboratory for testing. The doctor may ask for any variety of physical, microscopic and chemical tests. It is best to do most tests within 15 minutes from the time the urine was collected.

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Preparation & Expectations

What is involved in preparation for the test?

People may ask their doctors how to prepare for the test.

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Results and Values

What do the test results mean?

Normal test results for urine are:

color: varies from colorless to dark yellow. Certain foods may stain it.

specific gravity: ranges from 1.006 to 1.030. The higher the number, the more concentrated the urine.

pH, or relative acidity or alkalinity: ranges from 4.6 to 8.0. The average is 6.0, which is slightly acidic.

sugars, ketones, and proteins: None present.

blood: no red blood cells or hemoglobin are present.

bilirubin: none.

white blood cells: none.

Abnormal test results for urine are:

color: other than normal.

specific gravity: higher or lower values. This may indicate kidney disorders. Exceptions are those related to food or liquid intake.

pH: overly acidic or alkaline urine. This warrants medical attention.

sugar and ketones,usually tested together: high levels of glucose and ketones may indicate diabetes.

protein: any present may indicate kidney disorders.

blood: any present may indicate bleeding from the kidney, a urinary tract infection, or trauma from rigorous exercise.

bilirubin: any present indicates liver or bile duct disease.

nitrites and white blood cells: their presence indicates a urinary tract infection.

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Attribution

Author:David T. Moran, MD
Date Written:
Editor:
Edit Date:
Reviewer:Eileen McLaughlin, RN, BSN
Date Reviewed:05/04/01