What is urinalysis?
A urinalysis is a laboratory test. It can help your doctor detect problems with your body that may be indicated by your urine.
Many illnesses and disorders affect how your body removes waste and toxins. The excretory system includes your lungs, kidneys, urinary tract, skin, and bladder. Problems with any of these body parts can affect the appearance, concentration, and content of your urine.
Urinalysis is not the same as a drug screening or pregnancy test, although all three tests involve a urine sample.
Why urinalysis is done
Urinalysis is often used prior to surgery, as a preemptive screening during a pregnancy checkup, or as part of a routine medical or physical exam. Your doctor may also order urinalysis if they suspect that you have certain conditions, such as:
- kidney disease
- liver disease
- urinary tract infection
If you’ve already been diagnosed with any of these conditions, your doctor may use urinalysis to check on the progress of treatments or the progression of a disease.
Your doctor may also want to do a urinalysis if you experience certain symptoms, including:
- abdominal pain
- back pain
- blood in the urine
- painful urination
Preparing for urinalysis
Before your test, make sure to drink plenty of water so that you can give an adequate urine sample. You don’t have to fast or change your diet for the urinalysis test.
Also, tell your doctor about any medications or supplements you’re taking. Medications or supplements that can affect the results of your urinalysis include:
- vitamin C supplements
- anthraquinone laxatives
Some illegal drugs can affect your results as well. Tell your doctor about any substances you use before doing a urinalysis.
About the urinalysis process
You give a urine sample at the doctor’s office, hospital, or specialized testing facility. You’ll be given a plastic cup to take to the bathroom. There, you can privately urinate into the cup. If you have too much urine for the cup, finish urinating in the toilet.
You may be asked to obtain a clean catch urine sample. This technique helps prevent bacteria from the penis or vagina from getting in the sample. Begin by cleaning the genitalia around the urethra with a pre-moistened cleaning wipe that the doctor will provide. Urinate a small amount into the toilet, and then collect the sample in the cup. Avoid touching the inside of the cup so you don’t transfer bacteria from your hands to the sample.
When you’re finished, place the lid on the cup and wash your hands. You’ll either bring the cup out of the bathroom or leave it in a designated compartment inside the bathroom.
In some cases, your doctor may request that you do the urinalysis using a catheter inserted into your bladder through your urethra. This procedure may cause mild discomfort. If you’re uncomfortable with this method, ask your doctor if there are any alternate methods that you’re more comfortable with.
After you provide your sample, you’ve completed your portion of the test. The sample will then be sent to a lab or remain in the hospital if they have the necessary equipment.
Methods of urinalysis
Your doctor will then use one or more of the following methods to examine your urine.
In the microscopic exam, your doctor looks at drops of your urine under a microscope. They look for:
- abnormalities in your 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 yeasts
- epithelial cells, which can indicate a tumor
For the dipstick test, your doctor inserts a chemically treated plastic stick into your urine sample. The stick changes color based on the presence of certain substances in the urine. This test can help your doctor look for:
- bilirubin, a product of red blood cell death
- concentration or specific gravity
- pH levels or acidity
High concentrations of particles in your urine can indicate that you’re dehydrated. High pH levels can indicate urinary tract or kidney issues. And any presence of sugar can indicate diabetes.
Your doctor can also examine the sample for abnormalities, such as:
- clouded appearance, which can indicate an infection
- abnormal odors
- reddish or brownish appearance, which can indicate blood in your urine
Getting the results
When your urinalysis results are available, your doctor will review them with you.
If your results appear abnormal, there are two options. If you’ve previously been diagnosed with kidney problems, urinary tract problems, or other related condition, your doctor may order further tests to identify the cause of the abnormal contents of your urine. If you have no other symptoms of an underlying condition and a physical exam shows that your overall health is normal, your doctor may not require a follow-up.
If you have protein in your urine
Your urine normally contains a negligible level of protein. Sometimes, protein levels in your urine can spike due to:
- excessive heat or cold
- stress, both physical and emotional
- excessive exercise
These factors aren’t usually a sign of any major issues. But abnormally high levels of protein in your urine can be a sign of underlying issues that can cause kidney disease, such as:
- heart conditions
- hypertension (high blood pressure)
- sickle cell anemia
- rheumatoid arthritis
Your doctor may order follow-up tests to identify any conditions causing abnormally high protein levels in your urine.
Following up after a urinalysis
Abnormal urinalysis results typically require additional screening methods to adequately determine the cause. These can include:
- blood tests
- imaging tests such as CT scans or MRIs
- comprehensive metabolic panel (CMP)
- urine culture
- complete blood count (CBC)
- liver or renal panel