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Fine Granular Casts, Urine — Microscopy

Published: August 9, 2026Updated: August 17, 2026

A urine microscopy test that looks for fine granular casts, small structures that may form in the kidney tubules.

Quick summary

["Fine granular casts in urine may reflect temporary kidney stress or underlying kidney disease."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
32680-1
Short code
Fine Gran Casts #/area UrnS LPF
Synonyms
Fine Gran Casts #/area UrnS LPF
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-lpf
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 fine granular casts. These casts are small structures that can form inside the kidney's filtering tubules and then pass into the urine.

Why might I need this test?

A clinician may order urine microscopy to look for signs of kidney irritation, reduced kidney function, or dehydration. It is usually interpreted with other urine and blood test results rather than as a stand-alone diagnosis.

How is the test performed?

A urine specimen is prepared for microscopic analysis, and a laboratory professional examines the urine sediment to identify and report the types and amount of casts present. The result is generally qualitative or semiquantitative.

How do I prepare for the test?

Follow the collection instructions provided by your clinician or laboratory. Urine microscopy often uses a clean-catch, midstream urine sample, which should be collected in the supplied sterile container and delivered promptly.

Reference range

Adult: 10-40 U/LN/A

Specimen: urine

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine fine granular casts

Frequently asked questions

What are fine granular casts?
They are microscopic structures composed of cellular debris or protein material that form within kidney tubules. They may be released into the urine and seen during microscopy.
Does finding fine granular casts mean I have kidney failure?
No. They can occur with temporary dehydration or other reversible causes and do not by themselves indicate kidney failure. Your clinician will interpret them along with kidney function tests, symptoms, and other urine findings.
Can this test be performed at home?
Usually, the sample is collected and analyzed by a laboratory because reliable identification of urine casts requires microscopy. Follow your laboratory's specific collection and storage instructions.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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