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Urine Casts (Other / Unspecified)

Casts are tiny tube-shaped particles that can show up in urine. This entry covers casts reported without a type; 'none seen' is the usual result.

AI-drafted. Awaiting verificationAlso called UA CastsLOINC 9842-6

What it is

Casts are tiny cylinder-shaped pieces of protein that form in the kidney's small tubes and wash out in urine. They take the shape of the tube they formed in. A lab looks for them under a microscope as part of a complete urinalysis and prints either 'none seen' or the type, such as hyaline or granular. This entry is for results where the lab prints just 'casts' or an unnamed type. Named types have their own entries.

Why it matters

Some kinds of casts are common and harmless, while others can point to a problem in the kidney, so the type usually matters more than the word 'present' alone. Clinicians read casts together with protein, blood and white cells in the urine, your symptoms and your kidney blood tests. If your report only says casts are present with no type, ask your clinician or the lab which type was seen.

If it’s high

'Present' means the lab saw at least one cast. A few hyaline casts can be a normal finding. Other types, such as red or white cell casts, can be linked to inflammation in the kidney and are looked at together with protein, blood and your symptoms. Which type was seen matters most.

Common causes

  • A few hyaline casts, which can be a normal finding
  • Concentrated urine
  • Red cell casts in people who play contact sports can be a normal finding
  • Kidney conditions that a clinician would sort out using the cast type, protein and blood in the urine

What can help

  • Ask which type of cast was seen and how many
  • Ask whether the rest of your urinalysis, such as protein and blood, changes what this means
  • Ask whether a repeat sample is needed

What can affect your result

  • Concentrated or very acidic urine, which favors cast formation
  • Hard exercise, including contact sports
  • How fresh the sample is and how it was handled
  • How the lab examines the sample, by analyzer or by a person at a microscope
  • Urine that sits for hours before testing can give unreliable results.
  • Casts form when urine is concentrated, moves slowly through the kidney tubes, or is very acidic, so the same person can have different findings on different days.
  • Results depend on how the lab looks at the sample, whether with an automated analyzer or by a person at a microscope.

Any time. A fresh midstream sample is best, and it should reach the lab or be refrigerated promptly. Reflects only the sample you gave. Casts can come and go as the cause changes.

When to talk to a clinician

Call a clinician promptly if you notice blood in your urine, new swelling in your legs or face, much less urine than usual, or fever with back or side pain.

Questions you could ask

  • Does this result matter for any kidney or urine condition I already have?
  • Which type of cast was seen, and how many?
  • Do my other urinalysis results, such as protein and blood, change what this means?
  • Should we repeat the urinalysis?

Questions people ask

My report says casts: none seen. Is that the usual result?

Yes. For example, Labcorp lists 'None seen' as the reference for casts on its complete urinalysis. A few hyaline casts can also be a normal finding, so check the range printed on your own report.

Are casts always a sign of kidney disease?

No. A few hyaline casts can be normal, and concentrated urine can produce casts. The type, how many were seen and the rest of your urinalysis are what matter.

What does LPF mean on my report?

LPF stands for low-power field, one view under the microscope at low magnification. Labs report cast counts per LPF.

Show the science and sources

For clinicians and researchers

Casts are cylindrical coagula of Tamm-Horsfall mucoprotein that trap the contents of the tubule lumen. They form in the distal convoluted tubule or collecting duct during urinary concentration or stasis, or when urinary pH is very low, and the predominant element defines the type: hyaline, erythrocyte, leukocyte, epithelial, granular, waxy, fatty or broad (AFP 2005, Table 6). Hyaline casts may be normal. AFP 2022 links RBC and WBC casts to glomerular disease and granular casts to tubular injury such as acute tubular necrosis, and AFP 2005 Table 6 also lists pyelonephritis and interstitial nephritis for WBC casts. Phase-contrast microscopy helps identify casts but is not common in office settings (AFP 2022). Labcorp's complete urinalysis prints a single 'Casts' line in /lpf with a reference of 'None seen' (sample report 003772), which is the pattern this entry captures. Typed casts have their own entries (urine-hyaline-casts, urine-granular-casts, urine-rbc-casts, urine-wbc-casts). LOINC has count-per-field, presence and type codes for casts.

LOINC 9842-6 (primary), 9439-1, 24124-0, 58436-7, 101248-3. Specimen: urine.

Sources

  1. Urinalysis: A Comprehensive Review, American Family Physician 2005;71(6):1153-1162 (2005)
  2. Office-Based Urinalysis: A Comprehensive Review, American Family Physician 2022;106(1):27-35B (2022)
  3. Urinalysis, Complete (test 003772) sample patient report with reference intervals, Labcorp (2026)
  4. LOINC codes verified with the NLM Clinical Tables LOINC search, U.S. National Library of Medicine

AI-drafted. Awaiting verification. Last reviewed 2026-10-03. How we build and check these pages.

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