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:

Alternative Names

Hyaline casts; Granular casts; Renal tubular epithelial casts; Waxy casts; Casts in the urine; Fatty casts; Red blood cell 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.

Normal Results

There are different types of casts. The presence of a few hyaline casts is normal.

What Abnormal Results Mean

Abnormal results may include:

This test may also show:


Landry DW, Bazari H. Approach to the patient with renal disease. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 116.

Review Date: 8/21/2011
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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