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Coarse Granular Casts, Urine — Microscopic Examination

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

A urine microscopy test that looks for coarse granular casts, which are small structures formed in the kidney's urine-producing tubules.

Quick summary

["Coarse granular casts in urine may reflect kidney stress, dehydration, or impaired kidney function."]

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

Key facts at a glance

LOINC
33393-0
Short code
Coarse Gran Casts #/area UrnS LPF
Synonyms
Coarse 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 urine under a microscope to look for coarse granular casts. Casts are small cylindrical structures that form inside the kidney's filtering tubules and are released into the urine.

Why might I need this test?

Urine microscopy may be ordered as part of a urinalysis or when a clinician is evaluating kidney injury, urinary symptoms, dehydration, or changes in kidney function. It can also help interpret other urine findings and the results of kidney blood tests.

How is the test performed?

A urine sample is collected and placed in a centrifuge so that the sediment can be examined under a microscope. The laboratory checks the sediment for casts, cells, and other microscopic material and may report the amount seen.

How do I prepare for the test?

Follow the laboratory's collection instructions, which may include providing a clean-catch, midstream urine sample. Your clinician or laboratory can tell you whether a first-morning sample is preferred. Drinking fluids may be requested, but fasting is generally not required for urine microscopy.

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 Coarse Granular Casts

Frequently asked questions

What does a coarse granular cast mean?
It is a microscopic structure made of material that has accumulated inside a kidney tubule. Its presence may suggest that the kidneys are under stress or that kidney function is impaired.
Is this the same as a urine protein test?
No. This test looks at urine sediment under a microscope, whereas a urine protein test measures protein in the liquid portion of the urine.
Does one abnormal result confirm kidney disease?
No. Urine casts must be interpreted with the rest of the urinalysis, medical history, examination, and laboratory results. Your clinician can explain whether the finding is significant in your situation.
  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