Physical Properties
| Parameter | Normal | Abnormal / Significance |
|---|
| Colour | Pale to dark yellow (straw to amber) | Red/pink → blood; brown/tea → bilirubin or myoglobin; orange → rifampicin or concentrated |
| Clarity / Appearance | Clear | Cloudy → WBCs (infection), crystals, or phosphaturia; frothy → protein |
| Specific Gravity | 1.005 – 1.030 | <1.003 → very dilute (diabetes insipidus, excess water); >1.030 → concentrated (dehydration) |
| pH | 4.5 – 8.0 (usually 5.5–6.5) | Very alkaline >7.5 → UTI with urease-producing bacteria (Proteus); acidic <5 → gout, acidosis |
Dipstick Results
| Parameter | Normal | If Positive / Abnormal — Means |
|---|
| Protein | Absent (trace may be normal on spot sample) | Kidney disease (nephropathy, glomerulonephritis, CKD); confirms with ACR (albumin:creatinine ratio); transient in fever, exercise |
| Glucose | Absent | Diabetes mellitus (blood glucose exceeds renal threshold ~10 mmol/L); renal glycosuria (glucose appears without high blood sugar) |
| Ketones | Absent | Diabetic ketoacidosis (DKA); prolonged fasting or low-carbohydrate diet; vomiting |
| Blood (haematuria) | Absent | UTI, kidney stones, bladder cancer (painless haematuria in older patients), glomerulonephritis; menstrual contamination in women |
| Leucocyte esterase | Absent | WBCs in urine (pyuria) → UTI, pyelonephritis |
| Nitrites | Absent | Bacteria converting urinary nitrates → nitrites; suggests UTI; gram-negative organisms (E. coli, Klebsiella) |
| Bilirubin | Absent | Liver disease, biliary obstruction, hepatitis; conjugated bilirubin in urine |
| Urobilinogen | Normal (small amount) | High → haemolysis, liver disease; absent → complete biliary obstruction |
Microscopy Results
| Finding | Normal | Significance |
|---|
| WBC (pus cells) | <5 per high power field | >5 WBC/hpf = pyuria → UTI, pyelonephritis, interstitial nephritis; sterile pyuria suggests TB |
| RBC (red blood cells) | <3 per high power field | Dysmorphic RBCs → glomerulonephritis; normal-shaped RBCs → UTI, stones, cancer |
| Bacteria | Absent | Significant bacteriuria (>10⁵ colonies/mL on culture) confirms UTI |
| Epithelial cells | Few squamous cells | Many squamous cells → contaminated sample; transitional cells → may need investigation |
| Casts | Hyaline casts only (benign, especially after exercise) | See below — different cast types indicate different diseases |
| Crystals | May be present | Uric acid crystals → gout; calcium oxalate → kidney stones; struvite → infection stones |
What Different Urine Casts Mean
| Cast Type | Disease Indicated |
|---|
| RBC casts (red blood cell casts) | Glomerulonephritis (inflammation of kidney filters) — pathological finding |
| WBC casts | Pyelonephritis (kidney infection) or interstitial nephritis |
| Granular casts | Chronic kidney disease (CKD) or acute tubular necrosis; "muddy brown" granular casts |
| Waxy / broad casts | Advanced CKD (end-stage renal disease); wide casts form in dilated tubules |
| Hyaline casts | Normal (benign); can increase with dehydration or exercise |
| Fatty casts | Nephrotic syndrome; "Maltese cross" pattern with polarised light |
How to Collect a Clean Catch Sample
Midstream Urine (MSU) Collection
1. Wash hands thoroughly. 2. Clean the urethral opening with the provided wipe (front to back for women). 3. Begin urinating, let the first stream go into the toilet (this clears the urethra). 4. Catch the MIDDLE portion of the stream into the sterile container. 5. Do not touch the inside of the container. 6. Deliver to the lab within 2 hours, or refrigerate (not freeze) if delayed. A poorly collected sample gives misleading results.
Questions to Ask Your Doctor
- I have protein in my urine — should I have an ACR test to quantify it?
- Are the RBCs in my urine dysmorphic — could this be glomerulonephritis?
- If I have leucocytes but no bacteria, could this be TB or interstitial nephritis?
- Should I recheck in 2 weeks if the dipstick was positive for blood?
- What is the significance of my specific gravity result?
Medical Disclaimer: This information is for educational purposes only. Urine test interpretation requires clinical correlation. Always discuss abnormal results with your doctor.