Fine Granular Casts, Urine — Microscopic Count (per High-Power Field)
A urine microscopy test that looks for fine granular casts in the urine and reports the number seen per high-power field.
["Fine granular casts are a urine microscopy finding that may be temporary or may reflect kidney-related inflammation or disease."]
Key facts at a glance
- LOINC
- 33224-7
- Short code
- Fine Gran Casts #/area UrnS HPF
- Synonyms
- Fine Gran Casts #/area UrnS HPF
- Category
- liver
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- 0.5 N/A – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- microscopy-light-hpf
- 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 a urine sample under a microscope to identify and count fine granular casts. Casts are small cylindrical structures formed inside kidney tubules, and the amount found can help provide information about kidney function or kidney irritation.
Why might I need this test?
A clinician may order urine microscopy as part of a urinalysis, especially when evaluating kidney problems, blood or protein in the urine, swelling, or changes in urination. Finding and counting casts can help interpret the results alongside other urine and blood tests.
How is the test performed?
A urine sample is collected and examined by a laboratory professional using microscopy. The number of fine granular casts observed in a specified microscopic field is reported, typically per high-power field.
How do I prepare for the test?
Follow the instructions provided by your healthcare professional or laboratory, which may include collecting a clean-catch urine sample. Tell the laboratory if you are pregnant, menstruating, or taking medicines that may affect the urine results, and bring any container or paperwork they specify.
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.
Fine granular casts can occasionally be seen with strenuous exercise, dehydration, or other temporary changes in urine concentration. When they persist or occur with abnormal urine protein, blood, or other signs of kidney injury, they may suggest kidney tubular or other kidney disease. Results should be interpreted by a healthcare professional together with the rest of your urinalysis and medical history.
Short name
Urine fine granular casts
Frequently asked questions
What are fine granular casts?
Does finding fine granular casts always mean I have kidney disease?
How is this test different from a routine urinalysis?
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