A urine microscopy report is the part of your urinalysis that describes what a laboratory actually saw under the lens after your sample was spun down. The dipstick strip gives a fast chemical snapshot; the microscopic examination looks at the solid material left behind and counts it: red blood cells, white blood cells, bacteria, yeast, crystals, casts and epithelial cells. That is why a single urine sample can produce a report with a dozen separate lines, each with its own unit and its own normal range.
In this article you will learn how the laboratory prepares the slide, why some samples get a microscopic exam and others do not, and what every line on the report means. Each finding is introduced briefly here and linked to a dedicated page if you want the full detail. The aim is orientation: by the end you should be able to look at your own report and know which line matters, which is routine, and which is worth a conversation with your clinician.
What urine microscopy actually is
Urine is not just water and dissolved salts. It also carries formed elements, meaning solid particles that keep a recognizable shape. Some of them are shed normally by the lining of the urinary tract. Others appear only when something is inflamed, infected, bleeding or filtering poorly. Microscopy is the only part of a routine urinalysis that identifies those particles by their appearance rather than by a chemical reaction.
That distinction matters, because chemistry can be fooled. A dipstick pad can react to hemoglobin released from broken-down red cells even when no intact cells remain. Microscopy answers a different question: are the cells physically there, how many, and what do they look like.
Where it sits in a full urinalysis
A complete urinalysis has three layers. The visual exam records color and clarity. The dipstick records around ten chemical pads, including pH, glucose, ketones, blood and protein. The microscopic exam is the third layer, and it is the one that requires a trained technologist or an imaging analyzer rather than a color chart. According to the Cleveland Clinic, these three parts are ordered together but not always performed together.
How the lab turns your sample into a slide
The preparation is standardized, and understanding it explains several quirks of the report. A measured volume of urine, usually about 10 to 12 milliliters, goes into a conical tube and is spun in a centrifuge for a few minutes. The heavier formed elements collect at the bottom as a pellet. Most of the clear liquid above is poured off, the pellet is resuspended in the small volume that remains, and a drop of that concentrate is placed on a slide.
Because the sample was concentrated before it was read, counts are not a direct measure of how many cells were in your bladder. They are counts in a standardized field of view of a standardized concentrate, which is exactly why the units look odd.
Manual microscopy versus automated analyzers
Many laboratories now run samples through an automated particle analyzer that photographs or flow-sorts the elements and classifies them by software. These instruments are fast and reproducible, and studies comparing them with a technologist at a microscope find close agreement for red cells, white cells and squamous epithelial cells. Agreement is weaker for casts and for unusual crystals, which is why most laboratories keep review rules that send selected samples to a human for a manual look.
When a lab adds the microscopic exam
You may have noticed that some of your past urinalyses had a microscopy section and others stopped at the dipstick. That is deliberate, and laboratories call it a reflex to microscopic. Rather than putting every sample under a lens, the laboratory sets rules: if the dipstick crosses certain thresholds, the microscopic exam is triggered automatically on the same sample, with no second visit needed.
The usual triggers are a positive blood pad, a positive protein pad, a positive nitrite pad and a positive leukocyte esterase pad. Two of those pads are worth understanding on their own, and we explain the bacterial byproduct behind one of them in our urine nitrite test guide and the white cell enzyme behind the other in our leukocyte esterase results guide. A raised protein pad is also a common trigger, and you can review what that pad detects in our urine protein test guide.
A clinician can also request microscopy directly, regardless of the dipstick, when there is a specific question in mind, such as monitoring known kidney disease or investigating visible blood.
Reading your microscopic report line by line
This is the section most people come for. The table below walks through every line you are likely to see, how the laboratory reports it, what a typical normal looks like in United States laboratories, and what a raised result can point to. Reference ranges vary between laboratories, so always read your own report against the range printed beside it.
| Finding | How it is reported | Typical normal | What a raised result can point to |
|---|---|---|---|
| Red blood cells | Count per high power field, or cells per microliter | 0 to 3 per high power field | Infection, stones, vigorous exercise, menstrual contamination, bladder or kidney disease |
| White blood cells | Count per high power field | 0 to 5 per high power field | Urinary tract infection, irritation, inflammation of the kidney |
| Bacteria | None, few, moderate, many, or a count per microliter | None or few | True infection, or skin and genital contamination of the sample |
| Yeast | Present or absent, sometimes graded | Absent | Yeast infection, contamination, diabetes, recent antibiotics |
| Squamous epithelial cells | Few, moderate, many per low power field | Few | Usually a poorly collected sample rather than disease |
| Renal tubular epithelial cells | Count per high power field | Rare or none | Injury to the filtering tubes of the kidney |
| Hyaline casts | Count per low power field | 0 to a few | Dehydration, fever, strenuous exercise; often not a disease sign |
| Cellular or granular casts | Count per low power field | 0 per low power field | Active kidney disease affecting the filters or tubes |
| Crystals | Type named, then few, moderate or many | Few common crystals can be normal | Stone-forming tendency, metabolic disorders, some medications |
| Mucus | Present or absent | Small amounts are normal | Irritation or contamination; rarely significant alone |
| Sperm | Present or absent | May be present, not a disease finding | Recent ejaculation; noted for completeness only |
How counts are reported
Two units dominate. High power field, abbreviated HPF, is what the technologist sees at higher magnification, and it is used for small elements such as red cells, white cells and renal tubular cells. Low power field, abbreviated LPF, is a wider view used for larger structures such as casts and sheets of squamous cells. Automated analyzers often report cells per microliter instead, and your laboratory converts or prints both. Because the units differ, never compare a number from one laboratory directly with a number from another without checking which unit was used.
What raised findings can point to
Blood and inflammation
Red cells above the reference count are called hematuria, and the microscope adds something the dipstick cannot: the shape of the cells. Round, uniform cells usually come from somewhere along the drainage tract, such as a stone or the bladder wall. Distorted, irregular cells suggest the blood passed through the kidney filter itself. We unpack both patterns in our urine hematuria results guide. Raised white cells are covered separately in our urine white blood cells guide, and when the count is clearly elevated the report may use a single word for it, which we define in our pyuria test results guide.
Infection
Bacteria on a slide are suggestive but not conclusive, because a sample can pick up organisms on the way out. The combination that carries weight is bacteria plus white cells plus a matching dipstick pattern. We explain how laboratories grade the finding in our urine bacteria test guide, and the fungal equivalent in our yeast in urine results guide. When infection is genuinely suspected, microscopy is a screening step and the confirming test is a culture, which we walk through in our urine culture results guide.
Kidney-level clues
Casts are the most kidney-specific thing on the report. They form inside the small tubes of the kidney, taking the tube’s cylindrical shape, and whatever was floating in the tube gets trapped inside them. A cast full of red cells is strong evidence that bleeding started in the kidney rather than the bladder. We describe each type in our urinary casts results guide. Crystals are a different story, since many form after the sample cools rather than inside you, and we sort the harmless from the meaningful in our urine crystals results guide. Epithelial cells sit between the two, because their origin decides their meaning, as explained in our epithelial cells in urine guide.
Why timing and collection change your result
Microscopy is unusually sensitive to how the sample was handled, and this explains many results that look alarming but are not. A midstream clean-catch sample, collected after wiping and after letting the first stream pass, sharply reduces squamous cells and skin bacteria. A sample given straight into a cup without that step often shows many squamous cells, and a laboratory reading many squamous cells will frequently note that the specimen may be contaminated.
Time matters just as much. Left at room temperature, urine changes: bacteria multiply, red cells and fragile casts break down, and crystals can precipitate as the sample cools. Laboratories aim to read the sediment within about two hours or refrigerate it. If your sample sat in a car or a waiting room, a low red cell count or a lost cast may reflect the delay rather than your kidneys. The Mayo Clinic urinalysis overview makes the same point about collecting a clean sample.
When to see a doctor
A single abnormal line on a microscopic report is rarely an emergency by itself, but some combinations deserve prompt attention rather than watchful waiting. Contact a clinician without delay if you see visible blood in your urine, if you have fever with back or flank pain, if you have burning with urination that is worsening, or if you are passing very little urine. Book a non-urgent appointment if red cells are reported on two separate samples, if casts other than hyaline are reported, if renal tubular epithelial cells appear, or if bacteria and white cells are both raised without any symptoms. Bring the printed report, because the exact counts and units guide what happens next far better than a recollection of the summary line.
Latest scientific advances
Research published in the last three years has focused less on new findings under the lens and more on making the existing exam reliable and better targeted. Here is what has changed, in plain terms.
European laboratory medicine specialists published a full update of their urinalysis guideline in 2024, the first major revision in more than two decades. It sets out how samples should be collected, how particles should be counted, and how a laboratory should check a new automated instrument against microscopy before trusting it. What this means for you is that the units and thresholds printed on your report are converging internationally, so a count from one accredited laboratory should increasingly mean the same thing as a count from another.
A Johns Hopkins team tested what happens when a urine sample waits. Working with samples from intensive care patients, they re-measured the same urine at intervals across six hours and found that bacteria counts rose, while red blood cells and abnormal casts fell. Most other components held steady. What this means for you is simple and practical: a sample that sits around can overstate infection and understate bleeding or kidney findings, so a prompt drop-off, or a repeat sample if there was a long delay, genuinely improves the answer. This was a small study in one setting, so it points a direction rather than settling the question.
A hospital group in Brazil looked at which dipstick results should trigger a human being to look at the sediment. Reviewing several hundred samples, they found that a protein pad reading of one plus or more, or a blood pad reading of two plus or more, picked up roughly seven in ten of the samples that turned out to contain kidney-related findings, while still filtering out most of the rest. What this means for you is that the reflex rule deciding whether your sample gets a microscopic exam is now being set from evidence rather than habit, though each laboratory still tunes it to the patients it serves.
On the instrument side, a Belgian and Finnish team evaluated a newer flow cell analyzer, meaning a machine that photographs particles as they stream past a camera, against a technologist using phase-contrast microscopy on more than a thousand fresh samples. Agreement was very close for red cells, white cells and squamous cells, and noticeably better than older machines for telling crystal types apart. Agreement was weakest for casts. What this means for you is that automation is now trustworthy for the everyday lines on your report, while the kidney-specific lines still benefit from human review.
Finally, a review in a clinical chemistry journal surveyed how artificial intelligence is being applied to urinalysis, from classifying sediment images to screening for urinary tract infection. The authors concluded that results so far are encouraging but come almost entirely from studies looking backward at stored data, and that large studies following patients forward are still needed. What this means for you is that these tools are arriving in laboratories, but they support the technologist rather than replace them, and a clinician still interprets the result in the context of your symptoms.
Glossary
| Term | Definition |
|---|---|
| Sediment | The solid material that collects at the bottom of the tube after urine is spun in a centrifuge. It is the part placed on the slide and read under the microscope. |
| Formed elements | Any particle in urine that keeps a recognizable shape, including cells, casts, crystals and organisms. |
| High power field (HPF) | The circle of view at higher magnification. Small elements such as red and white blood cells are counted per HPF. |
| Low power field (LPF) | The wider circle of view at lower magnification, used to count larger structures such as casts. |
| Cast | A cylinder of protein formed inside a kidney tube, which may carry trapped cells. Casts indicate that a finding came from the kidney itself. |
| Dysmorphic red blood cell | A red blood cell with a distorted shape, suggesting it was damaged while passing through the kidney filter. |
| Reflex to microscopic | A laboratory rule that automatically adds the microscopic examination to the same sample when specific dipstick results are positive. |
| Midstream clean catch | A collection method in which the area is wiped and the first part of the stream is discarded, reducing contamination of the sample. |
| Phase-contrast microscopy | A microscope setting that increases contrast in transparent structures, making pale casts and cell outlines easier to see. |
| Squamous epithelial cell | A large flat cell shed from the outer urinary opening or the genital skin. Many of them usually signal a contaminated sample. |
FAQ
What is a normal range for urine microscopy?
Most United States laboratories report zero to three red blood cells and zero to five white blood cells per high power field as normal, with casts reported as zero per low power field apart from occasional hyaline casts. Bacteria, yeast and renal tubular cells are normally absent or rare, while a few squamous cells and a few common crystals are acceptable. These figures come from reference intervals each laboratory validates for its own instruments and population, so the range printed beside your result is the one that applies to you.
What are pus cells on a urine microscopy report?
Pus cells is an older term still used on some reports for white blood cells seen in the sediment. It does not mean visible pus in your urine. The count is read the same way as any white cell count, per high power field, and the interpretation is the same: a few can be normal, while a clearly raised number suggests infection or inflammation somewhere in the urinary tract. If your report uses this wording, read it as the white blood cell line.
What does an abnormal urine microscopy result mean?
It means one or more elements were seen in numbers above the reference range, or an element that should be absent was present. On its own that is a signal to look further, not a diagnosis. The same finding can come from an infection, a stone, a recent hard workout, a menstrual period, a medication, or simply a sample that was collected imperfectly or read late. Your clinician weighs the pattern across all the lines, your symptoms and any previous results before deciding whether anything needs to be done.
Do I need a urine culture as well as microscopy?
Not always. Microscopy can suggest infection when bacteria and white cells appear together, but it cannot name the organism or predict which antibiotic will work. A culture does both, and it is usually added when symptoms point to infection, when the sediment and dipstick agree, when you are pregnant, or when a previous treatment failed. If the sediment is clean and you have no symptoms, a culture is often unnecessary.
Why did my epithelial cell count come back high?
Most often because of how the sample was collected rather than because anything is wrong. Squamous cells are shed from the skin around the urinary opening, so a sample taken without wiping first, or without letting the first part of the stream pass, picks them up in quantity. Laboratories often flag such samples as possibly contaminated and may ask for a repeat. Renal tubular epithelial cells are a different matter and are followed up, since they come from inside the kidney.
How long does a urine microscopy result take?
The examination itself takes minutes once the sample reaches the bench, and many outpatient laboratories release the full urinalysis, including the microscopic section, on the same day. Delays usually come from transport rather than analysis. Because the sediment changes over hours at room temperature, laboratories prefer to read it quickly or refrigerate the sample, so dropping your specimen off promptly helps both the speed and the accuracy of the result.
Sources
- A.D.A.M. Health Solutions — Urinalysis — MedlinePlus Medical Encyclopedia, National Library of Medicine, reviewed 2025 — medlineplus.gov
- Cleveland Clinic — Urinalysis: What It Is, Purpose, Procedure, Results and Types — Cleveland Clinic Diagnostics and Testing, reviewed 2024 — my.clevelandclinic.org
- Mayo Clinic — Urinalysis — Mayo Clinic Tests and Procedures, 2025 — mayoclinic.org
- Kouri TT, Hofmann W, Falbo R, Oyaert M, et al. — The EFLM European Urinalysis Guideline 2023 — Clinical Chemistry and Laboratory Medicine, 2024 — doi.org/10.1515/cclm-2024-0070
- Parikh PC, Souza SD, Obeid W — Changes in the composition of urine over six hours using urine dipstick analysis and automated microscopy — BMC Nephrology, 2025 — doi.org/10.1186/s12882-024-03933-z
- Freitas PAC, da Silva YDS, Poloni JAT, Veronese FJV, Goncalves LFS — Dipstick Proteinuria and Hematuria as Triggers for Manual Microscopic Review in Nephrology Patients — Journal of Clinical Medicine, 2025 — doi.org/10.3390/jcm14134522
- Oyaert M, Kouri T, Carton E, Deprez S, Lambrecht S, Speeckaert M — Evaluation of AUTION EYE AI-4510 flow cell morphology analyzer for counting particles in urine — Clinical Chemistry and Laboratory Medicine, 2025 — doi.org/10.1515/cclm-2024-1163
- De Bruyne S, De Kesel P, Oyaert M — Applications of Artificial Intelligence in Urinalysis: Is the Future Already Here? — Clinical Chemistry, 2023 — doi.org/10.1093/clinchem/hvad136
Further reading
- Check how concentrated your sample was before you judge any count by reading our urine specific gravity results guide.
- Compare what you can see in the cup with what the laboratory measures using our urine color chart guide.
- Explore the infection that most often explains raised bacteria and white cells in our urinary tract infection guide.
- Understand why certain crystals matter by reading our kidney stones symptoms and treatment guide.
- Follow up a report showing casts or tubular cells with our chronic kidney disease guide.
Understand your lab results with BloodSense
A microscopic report is a list of counts and units, and the meaning lives in how those lines fit together rather than in any single number. BloodSense reads your urinalysis alongside related results such as urine protein, urine creatinine and a urine culture, and explains in plain language what each line describes and which ones are worth raising with your clinician. It helps you understand your report and prepare better questions; it does not diagnose and it does not replace your doctor.
