Definition of Urinary casts:

Urinary casts are tiny tube-shaped particles made up of white blood cells, red blood cells, or kidney cells. They form in kidney structures called tubules. Casts are held together by a protein released by the kidney. The content of a cast can tell your health care provider whether your urine is healthy or abnormal.

Types of urinary casts include:

• Fatty casts
• Granular casts
• Hyaline casts
• Red blood cell casts
• Renal tubular epithelial casts
• Waxy casts
• White blood cell casts

How the test is performed:

A clean-catch (midstream) urine sample is needed, preferably the first morning urine sample. For information on how to collect this sample, see: Clean-catch urine culture

How to prepare for the test:

No special preparation is needed.

How the test will feel:

The test involves only normal urination, and there is no discomfort.

Why the test is performed:

Your doctor may order this test to see if your kidneys are working properly and to check for certain conditions such as kidney infections, glomerular disease, and interstitial kidney disease.