Broad Waxy Casts, Urine — Microscopy
A urine microscopy test that looks for broad waxy casts, which may be associated with advanced or longstanding kidney disease.
["Broad waxy casts in urine can be an important sign of reduced kidney function, especially when kidney disease is longstanding."]
Key facts at a glance
- LOINC
- 41174-4
- Short code
- Broad Waxy Casts UrnS Ql Micro
- Synonyms
- Broad Waxy Casts UrnS Ql Micro
- Category
- liver
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- microscopy-light
- CPT
- 84484
- SNOMED
- 302774002
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This test examines urine under a microscope to look for broad waxy casts. These are structures formed inside kidney tubules and are not normally found in urine.
Why might I need this test?
Your clinician may order urine microscopy to evaluate kidney function or investigate possible kidney disease, dehydration, or a condition affecting the urinary tract.
How is the test performed?
A urine sample is collected and prepared for microscopic examination. A laboratory professional examines the urine sediment and reports whether broad waxy casts are present.
How do I prepare for the test?
Follow your clinician's collection instructions. Urine is often collected as a clean-catch, midstream sample, and the sample should be analyzed promptly. Ask your care team whether you need to avoid vigorous exercise beforehand or follow any fluid restrictions.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Broad waxy casts may occur with advanced or longstanding chronic kidney disease and severely reduced kidney function. They can also occasionally be seen during marked dehydration. This finding should be interpreted with other urine tests, kidney function tests, symptoms, and your medical history because it is not diagnostic by itself.
Short name
Urinary broad waxy casts
Frequently asked questions
What are broad waxy casts?
Does finding broad waxy casts mean I definitely have kidney failure?
Can this test be normal even when kidney function is reduced?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy