🔍 Urine analysis (urinalysis) is a fundamental diagnostic tool that provides valuable information about a patient's health. It involves the physical, chemical, and microscopic examination of urine to detect disorders such as urinary tract infections (UTIs), kidney disease, and diabetes.

🧩 Components of Urine Analysis

1️⃣ Physical Examination

💧 Colour: Normal urine ranges from pale yellow to amber.
- 🔴 Red/Pink → Hematuria (blood), beetroot, medications.
- 🤎 Brown/Black → Myoglobinuria, liver disease, drugs.
🌫️ Clarity: Should be clear. Cloudiness may mean bacteria, blood, sperm, crystals, or mucus.
👃 Odor: Normal = mild. Strong/foul can indicate infection, metabolic disorders, or dietary causes (e.g., asparagus).
⚖️ Specific Gravity: 1.005–1.030. ↑ suggests dehydration, ↓ suggests overhydration or renal impairment.

2️⃣ Chemical Examination

🧪 A urine dipstick is used to detect key substances:

pH 📏: Normal 4.5–8. Abnormal → renal disease, UTI, metabolic derangements.
Protein 🧬: Proteinuria may indicate kidney disease, HTN, or diabetes.
Glucose 🍬: Glycosuria suggests diabetes mellitus.
Ketones ⚡: Ketonuria suggests uncontrolled diabetes, starvation, or keto diet.
Bilirubin & Urobilinogen 💛: May indicate liver disease or haemolysis.
Blood 🩸: From infection, stones, trauma, or glomerular disease.
Leukocyte Esterase 🦠: WBCs present → UTI.
Nitrites 🔄: Suggest bacterial infection (Gram-negative organisms).

3️⃣ Microscopic Examination

🔬 Urine sediment examined for cells, casts, crystals, and organisms:

Red Blood Cells 🩸: Infection, stones, or glomerular disease.
White Blood Cells ⚪: Suggest infection/inflammation.
Epithelial Cells 🧫: Few = normal; ↑ = contamination or pathology.
Casts 🧱:
- Hyaline = often normal (post-exercise).
- Red Cell = glomerulonephritis.
- White Cell = pyelonephritis, interstitial nephritis.
Crystals 💎: Indicate stone risk or metabolic disorders.
- Uric Acid = gout, chemotherapy.
- Calcium Oxalate = kidney stones, ethylene glycol poisoning.
Bacteria 🦠: With WBCs → infection.
Yeast 🍞: May indicate fungal UTI (e.g., diabetics).
Parasites 🪱: Rare, e.g., schistosomiasis.

📊 Table of Key Findings

Finding	Associations
Casts 🧱
Red blood cells 🩸	Glomerulonephritis, vasculitis, interstitial nephritis
White blood cells ⚪	Interstitial nephritis, pyelonephritis
Epithelial cells 🧫	Acute tubular necrosis, interstitial nephritis, GN
Granular	Renal parenchymal disease (nonspecific)
Waxy/broad	Advanced renal failure
Hyaline	Normal in concentrated urine
Fatty	Heavy proteinuria (nephrotic syndrome)
Cells 🧬
Red blood cells 🩸	UTI, stones, glomerular disease
White blood cells ⚪	UTI, inflammation
Eosinophils 🟠	Allergic interstitial nephritis, atheroembolic disease
Squamous epithelial cells 🧫	Contaminants
Crystals 💎
Uric acid	Gout, tumour lysis
Calcium phosphate	Alkaline urine
Calcium oxalate	Stones, ethylene glycol poisoning
Cystine	Cystinuria
Sulfur	Sulfa drugs

✅ Conclusion

💡 Urine analysis is a quick, inexpensive, and valuable diagnostic tool. It can detect conditions ranging from simple UTIs to serious systemic disease. Mastery of this skill is essential for all clinicians.

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Abnormal urinalysis