# Urine Sediment: Cells, Casts, and the Source of Hematuria

Sediment identifies a likely compartment; the next decision depends on protein, kidney trajectory, systemic features, and persistent urologic risk.

![Infographic: Urine Sediment: Cells, Casts, and the Source of Hematuria](https://urinenephrology.org/visual-reference/images/student-urine-sediment.png?v=20261003c)

## Confirm and localize hematuria

Microscopy distinguishes intact RBCs from a heme-only reaction. Acanthocytes, dysmorphic RBCs, and RBC casts support a glomerular source, especially with proteinuria or rising creatinine. Isomorphic cells suggest a urologic source but do not exclude glomerular disease.

## Glomerular pattern: quantify and triage

Measure ACR or protein:creatinine ratio, trend creatinine, examine BP/edema, and ask about rash, joints, sinus symptoms, or hemoptysis. Rapid deterioration or pulmonary hemorrhage requires urgent nephrology assessment. Choose complement, ANCA, anti-GBM, or lupus tests from the syndrome rather than ordering every antibody reflexively.

## Tubular cells and granular casts

Renal tubular epithelial cells and coarse muddy-brown casts support acute tubular injury after ischemia, sepsis, toxins, or pigment injury. Correlate with exposure and timing. A bland sample does not exclude evolving injury, and a cast finding does not determine whether fluids are appropriate.

## White cells and crystals

WBCs or WBC casts can accompany pyelonephritis, interstitial nephritis, or inflammation. Fever/flank pain, cultures, and drug history separate these paths. Crystals need identification plus urine pH, medicines, and kidney trajectory; a crystal may be incidental rather than the cause of AKI.

## Improve the examination

Fresh urine and trained manual review matter when automated microscopy is unrevealing despite a strong clinical question. Phase contrast aids RBC morphology; polarized light identifies characteristic lipid or crystal behavior. Document specimen quality and the specific finding, not simply “active sediment.”

## Follow persistent hematuria

Repeat microscopy after treating a transient cause. AUA defines microhematuria as >3 RBCs/high-power field on a properly collected specimen; use risk-based urologic evaluation and nephrology review when renal disease is suspected. Anticoagulation does not remove the need to evaluate persistent bleeding.

## Supporting evidence

- [Supporting guideline or source](https://www.auanet.org/guidelines-and-quality/guidelines/microhematuria)
- [Supporting guideline or source](https://kdigo.org/wp-content/uploads/2016/10/KDIGO-2012-AKI-Guideline-English.pdf)
- [Supporting guideline or source](https://kdigo.org/guidelines/gd/)

## Source lessons

- [chapter 04 urinalysis](https://urinenephrology.org/nephrology-textbook/chapters/chapter-04-urinalysis.html)
- [enhanced student nephrology reference](https://urinenephrology.org/student-resources/foundations/enhanced_student_nephrology_reference.html)
- [urinalysis master diagnostic algorithm](https://urinenephrology.org/student-resources/foundations/urinalysis-master-diagnostic-algorithm.html)
- [urinalysis student handout](https://urinenephrology.org/student-resources/uti/urinalysis-student-handout.html)

Read alongside the full lessons; the findings and decisions shown here require the stated clinical context.