Urine Analysis

by Jan Zajc


Urinalysis should be performed to evaluate the following

  • Evaluation of renal & lower urinary tract abnormalities
  • Assessment of some metabolic/endocrine disorders
  • Assessment of hydration status

Urine Collection

  • Early Morning sample – qualitative
  • Random sample – routine
  • 24hr sample – quantitative estimation of proteins, Vanillyl mandelic acid, 5-hydroxyindole acetic acid, metanephrines, hormones in urine, microalbumin
  • Midstream sample – UTI
  • Postprandial sample – DM
  • Catheterise – infants, bedridden patients
  • Suprapubic needle aspiration

Urine Examination

Macroscopic Examination

  • Normal Volume – 600 – 2000mls
    • Polyuria – Diabetes Mellitus, Diabetes Insipidus, Polycystic Kidney, Chronic Renal Failure, Diuretics.
    • Oliguria – Dehydration, diarrhea, Excessive sweating, Acute glomerulonephritis, Acute tubular necrosis, Complete urinary tract obstruction
  • Color
    • Clear or yellow pale – normal due to pigments called urochrome
    • Milky – Purulent UTI, chyluria
    • Orange/Red – Urobilinogen, Red Beetroot ingestion, Hemoglobinuria, Haematuria
    • Brown/Black – alkaptonuria, melanin
  • Odor
    • Normal – aromatic due to the volatile fatty acids
    • Ammonical – bacterial action(E. coli) Fruity- ketonuria, starvation
    • Musty – Phenylketonuria
    • Fishy – UTI with Proteus
    • Rancid – Tyrosinemia
  • Urinary pH
    • Normal pH 4.6 – 8
    • Reflects the ability of the kidney to maintain normal hydrogen ion concentration in plasma & ECF
    • Acidic urine
      • Ketosis-diabetes,
      • starvation, fever,
      • systemic acidosis,
      • UTI by E.coli,
      • acidification therapy and high protein diet
    • Alkaline urine
      • Strict vegetarian,
      • Systemic alkalosis,
      • UIT by pseudomonas or Proteus,
      • alkalinization therapy,
      • CRF
  • Specific Gravity
    • Normal range- 1.003 to 1.035
    • High
      • All causes of oliguria,
      • Glycosuria,
      • DM,
      • Dehydration,
      • nephrotic syndrome
    •  Low
      • All causes of polyuria except glycosuria DI,
      • pyelonephritis,
      • glomerulonephritis
  • Osmolality
    • Normal – able to produce 500-850 mOsm/kg water
    • Dehydrated with normal renal function – 800 – 1400mOsm/kg water
    • Diuresis with normal renal function – 40 – 80 mOsm/kg water

Chemical Examination

  • Proteinuria
    • Glomerular proteinuria, e.g., nephrotic syndrome
    • Tubular proteinuria: e.g., acute n chronic pyelonephritis, heavy metal poisoning, TB kidney
    • Overflow proteinuria: Bence Jones proteins(plasma cell dyscrasia), hemoglobin( intravascular hemolysis), myoglobin(skeletal muscle trauma)
    • Hemodynamic proteinuria: seen in high fever, hypertension, heavy exercise, CCF etc.
    • Post-renal proteinuria: caused by inflammatory or neoplastic conditions in renal pelvis, ureter, bladder, prostate or urethra.
    • Microalbuminuria – Defined as urinary excretion of 30 to 300 mg/24 hrs of albumin in the urine
      • A prognostic marker for kidney disease
      • in diabetes mellitus (earliest sign of renal damage in DM)
      • in hypertension (sign of end-organ damage)
      • increasing microalbuminuria during the first 48 hours after admission predicts an elevated risk for acute respiratory failure, multiple organ failure, and overall mortality
    • Bence Jones proteins – monoclonal immunoglobulin light chains (kappa or lambda) synthesized by neoplastic plasma cells, seen in multiple myeloma, macroglobulinemias, primary amyloidosis
  • Sugars – Benedict’s test and Reagent Strip test
    • Glycosuria with hyperglycemia
      • diabetes,
      • acromegaly,
      • Cushing’s disease,
      • hyperthyroidism,
      • drugs like corticosteroids
    • Glycosuria without hyperglycemia
      • renal tubular dysfunction
  • Ketones
    • Acetone, Acetoacetic acid, β-hydroxybutyric acid
    • Non-diabetic causes- high fever, starvation, severe vomiting/ diarrhea, Glycogen storage disease
  • Bilirubin
    • Liver diseases
    • Injury,hepatitis
    • Obstruction to biliary tract
  • Urobilinogen
    • hemolytic jaundice
    • Early hepatitis
    • hepatocellular jaundice
  • Blood
    • Prerenal
      • bleeding diathesis,
      • hemoglobinopathies,
      • malignant hypertension
    • Renal
      • trauma,
      • calculi,
      • acute & chronic glomerulonephritis,
      • renal TB,
      • renal tumors
    • Postrenal
      • severe UTI,
      • calculi,
      • trauma,
      • tumors of the urinary tract

Microscopic Examination

The centrifuged sample of urine sediment is examined on a glass slide under high magnification after the supernatant is discarded

  • Acellular casts – Hyaline casts, Granular, Waxy, Fatty, Pigment casts and Crystal casts
    • Hyaline casts – Seen in fever, strenuous exercise, damage to the glomerular capillary
    • Granular casts – indicative of chronic renal disease
    • Waxy casts – severe longstanding kidney disease (end-stage renal disease)
    • Fatty casts – nephrotic syndrome, diabetic or lupus nephropathy, Acute tubular necrosis
    • Pigment casts – include those produced endogenously, such as hemoglobin in hemolytic anemia, myoglobin in rhabdomyolysis, and bilirubin in liver disease.
  • Cellular casts – Red cell casts, White cell casts, and Epithelial cell cast
    • Red Cell casts – The presence of red blood cells within the cast is always pathologic, and is strongly indicative of glomerular damage, usually associated with nephritic Syndrome
    • White Cell casts – Indicative of inflammation or infection, pyelonephritis, acute allergic interstitial nephritis, nephrotic syndrome, or post-streptococcal acute glomerulonephritis
    • Epithelial casts – seen in acute tubular necrosis and toxic ingestion, such as from mercury, diethylene glycol, or salicylate
    • Other structure – Bacteria, Microfilaria, Trichomonas Vaginalis, Schistosoma haematobium, Spermatozoa, Yeast.

How to perform urinalysis

Patients should be instructed clearly – using clean-catch, midstream specimen method is as accurate as catheterization. Urine should be checked immediately or refrigerated, but never left at room temperatures. In the tables are normal values.

Normal Urine Charactheristics

ColorPale to dark yellow
Urobilinogen0.2 – 1.0
Specific gravity
1.005 – 1.025
Leukocyte esterase


References and Further Reading

  • Strasinger, S. K., and Di Lorenzo, M. S. (2014) Urinalysis and body fluids. Philadelphia: F. A. Davis Company
  • Tintinalli, J. E., and Stapczynski, J. S. (2011) Tintinalli’s emergency medicine: a comprehensive study guide. New York:  McGraw Hill Medical
  • Marx, J. A. et al. (2010) Rosen’s emergency medicine: concepts and clinical practice. Philadelphia: Mosby Elsevier
  • https://respey.pbworks.com/f/Urinechracteristics.pdf