Crystals in Urine

What is a crystals in urine test?

A crystals in urine test checks a sample of your urine (pee) under a microscope to look for crystals. The test shows what the crystals are made of, how large they are, and how many are in your urine.

Urine crystals are formed in your kidneys. Your kidneys are two organs located below your rib cage, one on each side of your spine. They make urine when they filter your blood to remove waste products and extra water from your body.

Urine contains many dissolved substances, including extra minerals and acids your body doesn't need. Certain minerals in your urine may clump together with other substances and form solid crystals. This usually happens if your urine contains high levels of those minerals or has too much or too little acid.

Having a few small crystals in your urine is normal, and they usually don't cause problems. But large amounts of certain types of crystals may be a sign of a health condition that needs treatment.

Some types of crystals may stick together and make kidney stones. These are hard, pebble-like pieces of material that form in the kidneys. Small kidney stones may pass out of your body in your urine with little or no pain.

But without treatment, a large kidney stone may get stuck and block your urine flow. This can cause pain, bleeding, and serious damage to your kidneys and other parts of your urinary system. A crystals in urine test can help find the cause of kidney stones so you can get the right treatment to help prevent them.

Other names: urinalysis (crystals) microscopic urine analysis, microscopic examination of urine

What is it used for?

A crystals in urine test may be used to help diagnose or monitor several types of medical conditions linked to crystals in urine. These conditions include:

• Kidney stones and other kidney diseases
• Urinary tract infections (UTIs)
• Certain problems with metabolism (the process your body uses to make energy from the food you eat)

Crystals in urine testing is often part of a urinalysis, a test that measures different substances in your urine. It may be used to check your general health or to learn more about a possible health problem. A urinalysis may include a visual check of your urine sample, tests for certain chemicals, and an examination under a microscope to look for certain types of cells and crystals.

Why do I need a crystals in urine test?

You may have a crystals in urine test as part of a urinalysis to check your general health. You may also need this test if:

• You have symptoms of a kidney stone or urinary tract infection, which include:
  • Sharp pains in your lower abdomen (belly), side, groin, or back
  • Blood in your urine
  • Frequent need to urinate (pee)
  • Not being able to urinate at all or only urinating a little bit
  • Pain when urinating
  • Cloudy or bad-smelling urine
  • Nausea and vomiting
  • Fever and chills
• You have a condition that can cause kidney stones.
• You have had a kidney stone, and your health care provider needs to know your risk for developing another one.

What happens during a crystals in urine test?

You will need to give a urine sample for the test. Your provider may ask you to collect your sample using the clean catch method or a 24-hour urine test.

Clean Catch

A health care professional may give you a cleansing wipe, a small container, and instructions for how to use the "clean catch" method to collect your urine sample. It's important to follow these instructions so that germs from your skin don't get into the sample:

1. Wash your hands with soap and water and dry them.
2. Open the container without touching the inside.
3. Clean your genital area with the cleansing wipe:
   • For a penis, wipe the entire head (end) of the penis. If you have a foreskin, pull it back first.
   • For a vagina, separate the labia (the folds of skin around the vagina) and wipe the inner sides from front to back.
4. Urinate into the toilet for a few seconds and then stop the flow. Start urinating again, this time into the container. Don't let the container touch your body.
5. Collect at least an ounce or two of urine into the container. The container should have markings to show how much urine is needed.
6. Finish urinating into the toilet.
7. Put the cap on the container and return it as instructed.

24-hour Urine Test

Your provider may ask you to collect all your urine during a 24-hour period. This test may provide more accurate results because the amount of crystals and other substances in your urine can vary throughout the day.

If you need to have a 24-hour urine sample test, you'll be given a special container and instructions for how to collect and store your urine sample. Your provider will tell you what time to start. The test usually includes the following steps:

• To begin, urinate in the toilet as usual. Do not collect this urine. Write down the time you urinated.
• For the next 24 hours, collect all your urine in the container.
• Store the urine container in a refrigerator or in a cooler with ice.
• 24 hours after starting the test, try to urinate if you can. This is your last urine collection.
• Return the container with your urine to your provider's office or the laboratory as instructed.

If you have hemorrhoids that bleed or are having your menstrual period, tell your provider before your test.

Will I need to do anything to prepare for the test?

You don't need any special preparations for a crystals in urine test. To make sure your test results are accurate, be sure to carefully follow all the instructions for providing your urine sample.

Are there any risks to the test?

There is no known risk to having a crystals in urine test.

What do the results mean?

The test results will usually show if you have any crystals in your urine, the amount, and what they are made of. It's best to ask your provider to explain what your results mean. That's because different types of crystals are linked to different medical conditions, and your provider may need to order other tests to make a diagnosis.

Some common types of crystals that may form stones in some people include:

• Calcium oxalate and calcium phosphate. These crystals are the most common cause of kidney stones.
• Uric acid and urates. Large amounts of these crystals may form when metabolic problems, such as gout and type 2 diabetes, make your urine too acidic.
• Struvite. Repeated urinary tract infections may cause large amounts of struvite crystals.

Having crystals in your urine doesn't always mean that you have a medical condition that needs treatment. Large amounts of some types of crystals may be caused by:

• Certain medicines, such as calcium-based antacids, some types of antibiotics, diuretics (water pills), and antiviral medicines (medicines that treat viruses)
• Your diet, especially eating too much animal protein, such as fish, shellfish, and organ meats
• Not drinking enough fluids

If you have questions about your test results and how you can prevent crystals in urine, talk with your provider.

Learn more about laboratory tests, reference ranges, and understanding results.