Urinary casts
Hyaline casts; Granular casts; Renal tubular epithelial casts; Waxy casts; Casts in the urine; Fatty casts; Red blood cell casts; White blood cell castsUrinary casts are tiny tube-shaped particles that can be found when urine is examined under the microscope during a test called urinalysis.
Urinalysis
Urinalysis is the physical, chemical, and microscopic examination of urine. It involves a number of tests to detect and measure various compounds th...
Urinary casts may be made up of white blood cells, red blood cells, kidney cells, or substances such as protein or fat. The content of a cast can help tell your health care provider whether your kidney is healthy or abnormal.
How the Test is Performed
The urine sample you provide may need to be from your first morning urination. The sample needs to be taken to the lab within 1 hour.
A clean-catch urine sample is needed. The clean-catch method is used to prevent germs from the penis or vagina from getting into a urine sample. To collect your urine, the provider may give you a special clean-catch kit that contains a cleansing solution and sterile wipes. Follow instructions exactly so that the results are accurate.
Clean-catch urine sample
A clean catch is a method of collecting a urine sample to be tested. The clean-catch urine method is used to prevent germs from the penis or vagina ...
How to Prepare for the Test
No special preparation is needed.
How the Test will Feel
The test involves only normal urination. There is no discomfort.
Why the Test is Performed
Your provider may order this test to see if your kidneys are working properly. It may also be ordered to check for certain conditions, such as:
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Glomerular disease
Glomerular disease
Glomerulonephritis is a type of kidney disease in which the part of your kidneys that helps filter waste and fluids from the blood is damaged....
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Interstitial kidney disease
Interstitial kidney disease
Interstitial nephritis is a kidney disorder in which the spaces between the kidney tubules become swollen (inflamed). This can cause problems with t...
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Normal Results
The absence of cellular casts is normal. The presence of a few hyaline casts is also normal. Hyaline casts are the most common type of urinary casts. They're made up of a protein call uromodulin and are often the result of conditions such as dehydration and strenuous exercise, as well as chronic kidney failure.
What Abnormal Results Mean
Abnormal results may include:
- Fatty casts are seen in people who have lipids in urine. This is most often a complication of nephrotic syndrome.
Nephrotic syndrome
Nephrotic syndrome is a group of symptoms and abnormal test results that include protein in the urine, low blood protein levels in the blood, high ch...
ImageRead Article Now Book Mark Article - Granular casts are a sign of many types of kidney diseases.
- Red blood cell casts mean there is a microscopic amount of bleeding from the kidney. They are seen in many kidney diseases.
- Renal tubular epithelial cell casts reflect damage to tubule cells in the kidney. These casts are seen in conditions such as renal tubular necrosis, viral disease such as cytomegalovirus (CMV) nephritis, and kidney transplant rejection.
Renal tubular necrosis
Acute tubular necrosis (ATN) is a kidney disorder involving damage to the tubule cells of the kidneys, which can lead to acute kidney failure. The t...
ImageRead Article Now Book Mark ArticleCytomegalovirus (CMV) nephritis
Cytomegalovirus (CMV) infection is a disease caused by a type of herpes virus.
ImageRead Article Now Book Mark ArticleTransplant rejection
Transplant rejection is a process in which a transplant recipient's immune system attacks the transplanted organ or tissue.
ImageRead Article Now Book Mark Article - Waxy casts can be found in people with advanced kidney disease and long-term (chronic) kidney failure.
Long-term (chronic) kidney failure
Chronic kidney disease is the slow loss of kidney function over time. The main job of the kidneys is to remove wastes and excess water from the body...
ImageRead Article Now Book Mark Article - White blood cell (WBC) casts are common with acute kidney infections and interstitial nephritis.
Your provider will tell you more about your results.
Risks
There are no risks with this test.
References
Judd E, Sanders PW, Agarwal A. Diagnosis and clinical evaluation of acute kidney injury. In: Johnson RJ, Floege J, Tonelli M, eds. Comprehensive Clinical Nephrology. 7th ed. Philadelphia, PA: Elsevier; 2024:chap 72.
Riley RS, McPherson RA. Basic examination of the urine. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 29.
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Female urinary tract - illustration
The female and male urinary tracts are relatively the same except for the length of the urethra.
Female urinary tract
illustration
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Male urinary tract - illustration
The male and female urinary tracts are relatively the same except for the length of the urethra.
Male urinary tract
illustration
-
Female urinary tract - illustration
The female and male urinary tracts are relatively the same except for the length of the urethra.
Female urinary tract
illustration
-
Male urinary tract - illustration
The male and female urinary tracts are relatively the same except for the length of the urethra.
Male urinary tract
illustration
Review Date: 8/20/2023
Reviewed By: Jacob Berman, MD, MPH, Clinical Assistant Professor of Medicine, Division of General Internal Medicine, University of Washington School of Medicine, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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