physical examination

• Physical examination of urine

  • Color
  • Transparency / Clarity
  • Specific Gravity
  • Odor
• Color


  • Pigments
  • Urochrome
  • Uroerythrin
  • Urobilin
• Urochrome


  Responsible for the yellow color of urine
• Urochrome is a product of endogenous metabolism and is produced by the body at a constant rate under normal conditions
• Dilute urine

  Pale Yellow
• Concentrated urine

  Dark yellow
• Uroerythrin


  A pink pigment evident in refrigerated specimens
• Urobilin


  An oxidation product of urobilinogen that imparts an orange-brown color to urine that is not fresh
• Abnormal urine color

  • Colorless to Pale Yellow
  • Dark Yellow
  • Amber
  • Orange
  • Yellow-green
  • Yellow-brown
  • Green
  • Blue Green
  • Pink
  • Red
  • Brown
  • Black
• Colorless to Pale Yellow


  Recent fluid consumption, Polyuria, Diabetes mellitus, Diabetes insipidus
• Dark Yellow, Amber, Orange

  Concentrated specimen, Bilirubin, Acriflavine, Nitrofurantoin, Phenindione
• Yellow-green, Yellow-brown

  Bilirubin oxidized to biliverdin
• Green, Blue Green

  Pseudomonas spp infection, Clorets, Indican, Methylene Blue, Phenol
• Brown, Black


  RBCs oxidized to methemoglobin, Homogentisic acid, Melanin or melanogen, Methyldopa or Levodopa, Metronidazole
• Presence of yellow foam indicates (+) Bilirubin
• Absence of yellow foam indicates (-) Bilirubin
• Examples of urine color

  • Green Urine
  • Red Urine
  • Yellow Urine
• Examples of abnormal urine color

  • Alkaptonuria
  • Black Urine
  • Ochronosis
  • Blue diaper syndrome
  • Purple Urine Bag Syndrome
  • Porphyria cutanea tarda
• Clarity


  A general term that refers to the transparency or turbidity of a urine specimen
• Common terminology used to report clarity

  • Clear
  • Hazy
  • Cloudy
  • Turbid
  • Milky
• Urine Color and Clarity Procedure

  1. Evaluate an adequate volume of specimen

  2. Use a well-mixed specimen

  3. View the urine through a clear container

  4. View the urine against a white background using adequate room lighting

  5. Maintain adequate room lighting

  6. Evaluate a consistent volume of urine
• Pathologic causes of turbidity

  • RBCs
  • WBCs
  • Bacteria
  • Yeast
  • Non-squamous epithelial cells
  • Abnormal crystals
  • Lymph fluid
  • Lipids
• Nonpathologic causes of turbidity

  • Squamous epithelial cells
  • Mucus
  • Amorphous crystals
  • Semen, spermatozoa
  • Fecal contamination
  • Radiographic contrast media
  • Talcum powder
  • Vaginal cream
• Laboratory correlations in urine turbidity

  • Acidic urine
  • Alkaline urine
• Determination methods for specific gravity

  • Refractometry
  • Urinometry
  • Reagent strip
  • Harmonic oscillation densitometry
• Specific Gravity

  Density of solution compared with density of similar volume of distilled water at a similar temperature
• Normal random specimens may range from approximately 1.002 to 1.035 depending on the patient’s amount of hydration
• Specimens lower than 1.002 probably are not urine
• Refractometry

  1. Indirect method based on refractive index

  2. Compensated to temperature

  3. Requires corrections for glucose and protein
• Urinometry

  1. Requires temperature correction

  2. Requires corrections for glucose and protein
• Reagent strip

  1. Principle: pKa change of polyelectrolyte

  2. Reagent sensitive to number of ions in the urine specimen
• Harmonic oscillation densitometry


  Frequency of sound wave changes in proportion to the density of the solution
• Odor

  • Aromatic
  • Foul, ammonia like
  • Fruity / Sweet
  • Rotting fish
  • Rancid butter
  • Sweaty feet
  • Mousy odor
  • Cabbage odor
  • Maple syrup odor
  • Bleach
  • Odorless
  • Rotten egg
• Aromatic

  Normal odor
• Foul, ammonia like odor


  Indicates infection
• Fruity / Sweet odor


  Indicates presence of ketones
• Rotting fish odor

  Indicates Trimethylaminuria
• Rancid butter odor


  Indicates Tyrosyluria
• Sweaty feet odor

  Indicates Isovaleric acidemia
• Mousy odor


  Indicates Phenylketonuria