Skip to content

Pathologic Casts, Urine — Qualitative, Microscopy

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

Urine microscopy checks for abnormal cast-like structures that may form in the kidney tubules and can provide clues about kidney injury or other urinary conditions.

Quick summary

["Pathologic casts in urine may reflect dehydration or kidney disease and should be interpreted along with symptoms and other test results."]

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

Key facts at a glance

LOINC
101248-3
Short code
Path casts UrnS Ql Micro
Synonyms
Path 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 for pathologic casts. Casts are cylindrical structures that can form inside the kidney's filtering tubules, usually when proteins or cells become concentrated in the urine.

Why might I need this test?

Urine cast microscopy may be ordered during evaluation of kidney disease, swelling, reduced urine output, urinary blood, or unexplained changes in kidney function. It can also help assess possible dehydration or damage to the kidney tubules.

How is the test performed?

A urine specimen is examined by a laboratory professional using microscopy to identify and describe any casts present. The result is generally reported as present or absent, with the type of cast noted when possible.

How do I prepare for the test?

Follow the collection instructions provided by your healthcare professional. A clean-catch urine sample is usually requested and should be delivered promptly; special timing or repeat collections may be required in some cases. Fasting is generally not necessary unless your clinician says otherwise.

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 cast microscopy

Frequently asked questions

What are urine casts?
Urine casts are small cylindrical structures formed inside kidney tubules and released into the urine. Different types can be associated with different kidney or urinary conditions.
Does finding casts always mean I have kidney disease?
No. Casts can be temporary or related to dehydration, and some findings are not concerning on their own. Your clinician will interpret the result with the rest of your health information.
Do I need to collect a 24-hour urine sample?
Usually, a single urine specimen is enough for cast microscopy. A timed or 24-hour collection is needed only if specifically requested by your clinician.
  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