Overview of urinalysis
A urinalysis is a test of your urine. A urinalysis is used to detect and monitor a wide range of disorders, such as urinary tract infections, kidney disease, and diabetes.
A urinalysis involves checking the appearance, concentration, and content of your urine. Abnormal urinalysis results may indicate illness or disease.
For example, a urinary tract infection can make urine look cloudy instead of clear. Elevated levels of protein in the urine can be a sign of kidney disease. Unusual urinalysis results often require further testing to discover the source of the problem.
Why it’s done?
A urinalysis is a common test done for several reasons:
- To check your general health. Your doctor may recommend a urinalysis as part of a routine medical exam, pregnancy checkup, pre-surgery preparation, or on admission to the hospital to screen for a variety of disorders, including diabetes, kidney disease, and liver disease.
- To diagnose a medical condition. Your doctor may suggest a urinalysis if you experience abdominal pain, back pain, frequent or painful urination, blood in your urine, or other urinary problems. A urinalysis can help diagnose the cause of these symptoms.
- To monitor a medical condition. If you’ve been diagnosed with a medical condition, such as kidney disease or urinary tract disease, your doctor may recommend regular urinalysis to monitor your condition and treatment.
Other tests, such as pregnancy tests and drug tests, may also rely on a urine sample, but these tests look for substances that are not included in a typical urinalysis. For example, pregnancy tests measure a hormone called human chorionic gonadotropin (HCG). Drug tests detect specific drugs or their metabolic products, depending on the purpose of the test.
Why get tested?
To detect, help diagnose and/or manage various diseases and conditions, such as kidney disorders or urinary tract infections (UTIs).
When to get tested?
When you have symptoms, such as abdominal pain, back pain, frequent or painful urination; sometimes as part of a health exam, pregnancy checkup, hospital admission, or pre-surgical evaluation.
How is the sample collected for testing?
One to two ounces of urine is collected in a clean container. A sufficient sample is required to obtain 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” urine sample. For this, it is important to clean the genital area before collecting urine. Bacteria and cells from the surrounding skin can contaminate the sample and interfere with the interpretation of the test results. In women, menstrual blood and vaginal secretions can also be a source of contamination.
Women should spread the labia and clean from front to back; men should clean the tip of the penis. Begin to urinate, allow some urine to run down the toilet, then collect one to two ounces of urine in the container provided, and then flush the rest down the toilet.
A urine sample will only be useful for a urinalysis if it is brought to the healthcare provider’s office or laboratory for processing in a short period of time. If more than an hour will elapse between collection and transport, then the urine must be refrigerated or a preservative can be added.
Is any test preparation needed?
No preparation is needed for the test.
How does the urinalysis test work?
There are three ways to test urine and your test can use all of them.
One is a visual exam, which checks for color and clarity. If your urine has blood in it, it may be red or dark brown. Foam can be a sign of kidney disease, while cloudy urine can mean you have an infection.
A microscopic exam looks for things too small to be seen otherwise. Some of the things that shouldn’t be in urine that a microscope can find include:
- Red blood cells
- White blood cells
- Crystals (groups of minerals, a possible sign of kidney stones)
The third part of the urinalysis is the dipstick test, which uses a thin plastic strip treated with chemicals. It is immersed in urine and the chemicals in the stick react and change color if the levels are above normal. Things the test strip test can check for include:
- Acidity or pH. If the acid is abnormal, you could have kidney stones, a urinary tract infection (UTI), or another condition.
- This can be a sign that your kidneys are not working well. The kidneys filter waste products from the blood.
- High sugar content is a marker of diabetes.
- White blood cells. These are a sign of infection or inflammation, either in your kidneys or elsewhere along your urinary tract.
- This means that there is an infection with certain types of bacteria.
- If this waste product appears, which is normally eliminated by your liver, it may mean that your liver is not working properly.
- Blood in your urine Sometimes this is a sign of infections or certain diseases.
You will give your urine sample at the doctor’s office, hospital, or a specialized testing center. You will be given a plastic cup to take to the bathroom. There, you can privately urinate into the cup.
You may be asked to obtain a clean urine sample. This technique helps prevent bacteria from the penis or vagina from entering the sample. Begin by cleaning around the urethra with a pre-moistened cleansing wipe provided by your doctor. Urinate a small amount down the toilet and then collect the sample in the cup. Avoid touching the inside of the beaker to avoid transferring bacteria from your hands to the sample.
When you’re done, put the lid on the cup and wash your hands. You will remove the toilet bowl or leave it in a designated compartment within the bathroom.
In some cases, your doctor may ask you to test your urine with a catheter that is inserted into the bladder through the urethra. This can cause slight discomfort. If you are not comfortable with this method, ask your doctor if there are alternative methods.
After providing your sample, you have completed your portion of the test. Then the sample will be sent to a lab or will stay in the hospital if they have the necessary equipment.
Then your doctor will use one or more of the following methods to test your urine:
- Microscopic examination
- On microscopic examination, your doctor looks at the urine droplets under a microscope. They look for:
- Abnormalities in red or white blood cells, which may be signs of infections, kidney disease, bladder cancer, or a blood disorder
- Crystals that may indicate kidney stones
- Infectious bacteria or yeast
- Epithelial cells, which may indicate a tumor
- Dipstick test
For the dipstick test, your doctor inserts a chemically treated plastic rod into your sample. The bar changes color depending on the presence of certain substances. This can help your doctor look for:
- Bilirubin, a product of the death of red blood cells
- Blood test
- Concentration or specific gravity
- Changes in pH or acidity levels
- High concentrations of particles in your urine can indicate that you are dehydrated. High pH levels can indicate urinary tract or kidney problems. And any presence of sugar can indicate diabetes.
- Visual examination
Your doctor may also examine the sample for abnormalities, such as:
- Cloudy appearance, which may indicate an infection.
- Abnormal odors.
- Reddish or brown appearance, which may indicate blood in the urine.