What is a crystal in urine test?
Your urine contains many chemicals. Sometimes these chemicals form solids, called crystals. A crystal in urine test looks at the amount, size, and type of crystals in your urine. It's normal to have a few small urine crystals. Larger crystals or specific types of crystals can become kidney stones. Kidney stones are hard, pebble-like substances that can get stuck in the kidneys. A stone can be as small as a grain of sand, as big as a pea, or even larger. While kidney stones rarely cause serious damage, they can be very painful.
Other names: urinalysis (crystals) microscopic urine analysis, microscopic examination of urine
What is it used for?
A crystal in urine test is often part of a urinalysis, a test that measures different substances in your urine. A urinalysis may include a visual check of your urine sample, tests for certain chemicals, and an examination of urine cells under a microscope. A crystal in urine test is part of a microscopic exam of urine. It may be used to help diagnose kidney stones or a problem with your metabolism, the process of how your body uses food and energy.
Why do I need crystals in urine tests?
A urinalysis is often part of a routine checkup. Your health care provider may include crystals in urine test in your urinalysis if you have symptoms of a kidney stone. These include:
- Sharp pains in your abdomen, side, or groin
- Back pain
- Blood in your urine
- Frequent urge to urinate
- Pain when urinating
- Cloudy or bad-smelling urine
- Nausea and vomiting
What happens during crystals in urine test?
You will need to provide a sample of your urine. During your office visit, you will receive a container to collect the urine and special instructions to make sure the sample is sterile. These instructions are often called the "clean catch method." The clean-catch method includes the following steps:
- Wash your hands.
- Clean your genital area with a cleansing pad. Men should wipe the tip of their penis. Women should open their labia and clean from front to back.
- Start to urinate into the toilet.
- Move the collection container under your urine stream.
- Collect at least an ounce or two of urine into the container, which should have markings to indicate the amount.
- Finish urinating into the toilet.
- Return the sample container as instructed by your health care provider.
Your health care provider may also request that you collect all urine during a 24-hour period. This is called a "24-hour urine sample test." It is used because the amounts of substances in the urine, including crystals, can vary throughout the day. Your health care provider or a laboratory professional will give you a container to collect your urine and instructions on how to collect and store your samples. A 24-hour urine sample test usually includes the following steps:
- Empty your bladder in the morning and flush that urine away. Record the time.
- For the next 24 hours, save all your urine passed in the container provided.
- Store your urine container in the refrigerator or a cooler with ice.
- Return the sample container to your health care provider's office or the laboratory as instructed.
Will I need to do anything to prepare for the test?
You don't need any special preparations for crystals in urine tests. Be sure to carefully follow all the instructions for providing a 24-hour urine sample.
Are there any risks to the test?
There is no known risk of having crystals in urine tests.
