Crystals in Urine

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.

Why this test is done

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.

How to prepare

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.

Sample type

Urine

Other names for this test

urinalysis (crystals) microscopic urine analysis, microscopic examination of urine