What is urinalysis?

A urinalysis is a laboratory test. It can help your doctor detect problems that may be shown by your urine.

Many illnesses and disorders affect how your body removes waste and toxins. The organs involved in this are your lungs, kidneys, urinary tract, skin, and bladder. Problems with any of these 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.

Urinalysis is often used:

  • prior to surgery
  • as a preemptive screening during a pregnancy checkup
  • as part of a routine medical or physical exam

Your doctor may also order this test if they suspect that you have certain conditions, such as:

If you already have a diagnosis for any of these conditions, your doctor may use urinalysis to check on the progress of treatments or the condition itself.

Your doctor may also want to do a urinalysis if you experience certain symptoms, including:

Before your test, make sure to drink plenty of water so you can give an adequate urine sample. However, drinking excessive amounts of water may cause inaccurate results.

One or two extra glasses of fluid, which can include juice or milk if your diet allows, is all you need the day of the test. You don’t have to fast or change your diet for the test.

Also, tell your doctor about any medications or supplements you’re taking. Some of these that can affect the results of your urinalysis include:

  • vitamin C supplements
  • metronidazole
  • riboflavin
  • anthraquinone laxatives
  • methocarbamol
  • nitrofurantoin

Some other drugs can affect your results as well. Tell your doctor about any substances you use before doing a urinalysis.

You’ll give your 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.

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 around your urethra with a premoistened cleaning wipe provided by the doctor. Urinate a small amount into the toilet, 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 done, 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 acatheterinserted into your bladder through your urethra. This may cause mild discomfort. If you’re uncomfortable with this method, ask your doctor if there are any alternate methods.

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.

Your doctor will then use one or more of the following methods to examine your urine:

Microscopic exam

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

Dipstick test

For the dipstick test, your doctor inserts a chemically treated plastic stick into your sample. The stick changes color based on the presence of certain substances. This can help your doctor look for:

  • bilirubin, a product of red blood cell death
  • blood
  • protein
  • concentration or specific gravity
  • changes in pH levels or acidity
  • sugars

高浓度的粒子在你的尿液indicate that you’re dehydrated. High pH levels can indicate urinary tract or kidney issues. And any presence of sugar can indicate diabetes.

Visual exam

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

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 conditions, your doctor may order further tests or another urinalysis 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.

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
  • fever
  • 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:

Your doctor may orderfollow-up teststo identify any conditions causing abnormally high protein levels in your urine.

If your urinalysis results come back abnormal, your doctor may require additional tests to determine the cause. These can include: