07/05/2025
Urine Analysis Details:
1. Types of Urine Analysis
- Physical examination
- Chemical examination
- Microscopic examination
2. Physical Examination (Macroscopic):
Test Normal Interpretation if Abnormal:
Color Pale yellow (urochrome pigment)
Red (blood),
Brown (myoglobin),
Dark yellow (dehydration)
Clarity Clear Cloudy (infection, crystals, mucus)
Odor Slight smell Foul (infection),
Sweet (ketones in diabetes)
Volume 800–2000 mL/day (normal)
High (polyuria),
Low (oliguria)
3. Chemical Examination (Urine Dipstick Method):
Test Normal Abnormal Findings:
pH 4.5 – 8
High: UTI;
Low: Acidosis
Specific Gravity 1.005 – 1.030
Low: Overhydration;
High: Dehydration
Protein Negative
Positive: Kidney disease (proteinuria)
Glucose Negative
Positive: Diabetes mellitus
Ketones Negative
Positive: Diabetic ketoacidosis, fasting
Blood Negative
Positive: Stones, infection, trauma
Bilirubin Negative
Positive: Liver disease
Urobilinogen Normal trace
Increased: Liver disease, hemolysis
Nitrites Negative
Positive: Bacterial infection (Gram-negatives)
Leukocyte esterase Negative
Positive: WBCs, infection
4. Microscopic Examination:
What is Seen Normal Interpretation
Red Blood Cells (RBCs) 0–2 / hpf Hematuria (infection, stones, trauma)
White Blood Cells (WBCs) 0–5 / hpf Infection (UTI)
Epithelial Cells Few Many: Contamination or pathology
Casts Rare hyaline casts RBC casts (glomerulonephritis), WBC casts (pyelonephritis)
Crystals Occasional Uric acid, calcium oxalate, infection-related crystals
Bacteria/Yeasts None Infection
Spermatozoa None May be normal after ej*******on
(hpf = high-power field under microscope)
5. Special Urine Tests
- 24-hour urine collection: For protein quantification, creatinine clearance measurement.
- Urine culture: To detect and identify infection-causing organisms.
- Urine cytology: For suspected urinary tract malignancies.
- Dipstick microalbuminuria: Early marker for diabetic nephropathy.
Note: Proper collection techniques (midstream clean-catch urine) and prompt examination are crucial for accurate results.
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Urine Analysis: Step-by-Step Laboratory Procedure:
1. :
Type of sample:
Midstream, clean-catch urine (preferred)
24-hour urine (for quantitative analysis)
Container:
Sterile, wide-mouthed, dry plastic container.
Labeling:
Patient name, ID, date, and time of collection.
: Process within 2 hours or refrigerate at 2–8°C.
2.
Steps:
1. Inspect the color and note it (pale yellow, red, brown, etc.).
2. Check clarity by holding up the urine against light (clear, cloudy, turbid).
3. Smell the sample (carefully) and note unusual odors (sweet, foul, ammoniacal).
4. Measure volume if it's a 24-hour sample.
5. Record observations.
3. (Dipstick Test)
Materials:
Urine reagent strip (dipstick)
Timer/stopwatch
Steps:
1. Mix urine gently (do not shake vigorously).
2. Dip the reagent strip into the urine for 1–2 seconds.
3. Remove excess urine by tapping the strip on the side of the container.
4. Wait the recommended time (as per strip manufacturer: usually 30–60 seconds).
5. Compare each pad's color with the chart on the bottle.
6. Record the results for:
pH
Specific gravity
Protein
Glucose
Ketones
Blood
Bilirubin
Urobilinogen
Nitrite
Leukocyte esterase
:
Avoid touching the test areas with fingers.
Use fresh, well-stored strips.
4.
Materials:
Centrifuge
Microscope
Glass slides and coverslips
Pipette
Steps:
1. Centrifuge 10–15 mL of urine at 1500–2000 rpm for 5 minutes.
2. Carefully decant the supernatant, leaving about 0.5 mL of sediment.
3. Resuspend the sediment by gently tapping.
4. Place one drop of sediment on a clean glass slide.
5. Cover with coverslip.
6. Examine under microscope:
Low power (10x): Look for casts, crystals, large cells.
High power (40x): Identify RBCs, WBCs, epithelial cells, bacteria, yeasts.
7. Record findings quantitatively (e.g., 2-5 RBCs/hpf).
Optional:
Phase contrast microscopy can improve visualization of crystals and casts.
5. (If Ordered)
:
Use a calibrated loop (0.001 mL) to inoculate culture media.
Incubate and report colony count (CFU/mL).
:
Centrifuge urine, fix sediment, and stain (e.g., Papanicolaou stain).
:
Use special dipsticks or immunoassay techniques.
General Precautions:
Always wear gloves and lab coat.
Handle specimens as potentially infectious.
Use biosafety cabinets for culture work.
Dispose of urine and materials properly after analysis.
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