Physical Examination of Urine

• Required urine volume for routine urinalysis: 10 to 15 mL, but collection of a larger volume is encouraged to ensure sufficient urine for additional or repeat testing
• Smaller volumes of urine (<12 mL), hinder performance of the microscopic examination when the urinalysis is performed manually and can limit the chemical tests performed
• Container capacity for routine urinalysis: 50 mL
• Types of examinations under urine urinalysis

  • Physical Examination
  • Chemical Examination
  • Microscopic Examination
• Average volume of urine for routine urinalysis: 12 mL
• Required volume range of urine for routine urinalysis: 10-15 mL
• Urine container capacity for drug testing: 60 mL
• Required volume of urine for drug testing: 30-45 mL
• Physical urinalysis


  Observation of these characteristics provides preliminary information concerning disorders, such as glomerular bleeding, liver disease, inborn errors of metabolism, and urinary tract infection
• Measurement of specific gravity aids in the evaluation of renal tubular function
• Color


  Serves as an indicator of how well hydrated a person is; it gives a rough estimate of urine concentration
• If a person keeps on drinking water, they will have a colorless to pale yellow urine
• Color should correlate with urine specific gravity. But in cases such as DM, patient have pale yellow colored urine but the SG is increased due to the presence of glucose
• Normal urine color common description

  • Pale yellow
  • Yellow
  • Dark yellow
  • Amber
• Urochrome (Yellow)


  • A product of endogenous metabolism, and under normal conditions, the body produces it at a constant rate. Amount produced is dependent on the body's metabolic state.
  • Increased in thyroid conditions, fasting states, fever and long standing at room temperature. Major pigment of urine
• Uroerythrin (Pink)


  In refrigerated specimen resulting in the precipitation of amorphous urates in an acid urine (pink sediments/ brick-red dust). Attached to the urates, producing a pink color to the sediment
• Urobilin (Dark Yellow or Orange)


  Oxidation product of urobilinogen. Imparts an orange-brown color to urine that is not fresh
• Urine Color and Clarity Procedure

  • Evaluate an adequate volume of specimen
  • Use a well-mixed specimen
  • View the urine through a clear container
  • View the urine against a white background using adequate room lighting
  • Maintain adequate room lighting
  • Evaluate a consistent volume of urine
  • Determine the urine color
• Abnormal urine color

  • Red, red brown
  • Dark yellow/ Amber/ Orange
  • Pink/ Brown
  • Blue/ Green
• Causes of colorless to pale yellow urine

  • Recent fluid consumption (inc. alcohol)
  • Polyuria
  • Diabetes insipidus
  • Diabetes mellitus
• Causes of dark yellow, amber, yellow brown urine

  • Mepacrine (yellow) (anti-malarial drug)
  • Riboflavin (bright yellow) (Vit. B2)
  • Concentrated specimen (inc. urochrome)
  • Bilirubin (has yellow foam)
  • Urobilin
  • Acriflavine (anticoagulant)
  • Nitrofurantoin (antibiotic for UTI)
• Causes of orange, orange-red urine

  • Phenazopyridine (Pyridium) (for UTI, has a yellow foam that is sometimes mistaken as bilirubin)
  • Phenindione
  • Carotene
  • Warfarin (coumadin) (anticoagulant)
  • Rifampin (antibiotic for TB)
• Causes of dark yellow-green, yellow brown urine

  • Bilirubin oxidized to biliverdin
• Urine foam


  Not reported in routine urinalysis but it can serve as a preliminary or supportive evidence for physical examination of urine
• Yellow foam

  • Bilirubin (conjugated) - Bilirubin 2. Bilirubin 1 is conjugated with albumin and once it passes through the glomerulus it will not be filtered because albumin is big thus it will not be excreted in the urine.
  • Phenazopyridine (brand name: pyridium) - yellow foam, bright-orange urine
• White, stable foam

  • Concentrated urine
  • Presence of protein
• Phenazopyridine


  • Thick, orange pigment not only obscures the natural color of the specimen but also interferes with chemical tests that are based on color reactions.
  • Specimens containing phenazopyridine produce a yellow foam when shaken, which could be mistaken for bilirubin
• Causes of pink/brown urine

  • Presence of blood
  • Red blood cells (RBCs) remaining in an acidic urine for several hours cause the urine to turn brown
  • Fresh brown urine may indicate: Glomerular bleeding
  • RBCs in urine: red and cloudy
  • Hemoglobin and Myoglobin - red urine & (+) for blood chemical test
  • Hemoglobinuria and myoglobinuria may be possible by examining the patient’s plasma
  • Fresh urine containing myoglobin exhibits a more reddish-brown color
  • Urine with porphyrins may appear red often referred to a color of “port wine” or “burgundy wine”
• Nonpathologic causes of red urine

  • Menstrual contamination
  • Ingestion of highly pigmented foods and/or medications
  • Ingestion of blackberries can produce a red color in acidic urine
  • Medications: Rifampin, Phenolphthalein, Phenindione, and Phenothiazines
• Causes of red to brown brown urine

  • Phenol derivatives
  • Levodopa
  • Methyldopa
  • Metronidazole
• Causes of green urine

  • Pseudomonas
  • Clorets (breath deodorizer)
  • Phenol derivatives
• Melanin


  Oxidation product of the colorless pigment melanogen, which is produced in excess when a malignant melanoma is present
• Causes of pink red urine


  • RBCs
  • Hemoglobin
  • Myoglobin - red to brown
  • Menstruation
  • Beets
  • Blackberries
  • Phenolsolfonpthalein
  • Phenindione
  • Phenothiazines
  • Senna - laxative
• Hematuria


  Intact RBC in urine, urine is cloudy pink to red
• Causes of red or brown urine

  • Myoglobin (25 mg/dL)
• Port wine or red purple urine

  • Porphyrins
  • Purgative (alkaline pH)
• Homogentisic acid

  A metabolite of phenylalanine, imparts a black color to alkaline urine from patients with the inborn error of metabolism, called alkaptonuria
• Medications which produce brown/black urine

  • Phenol derivatives
  • Levodopa
  • Methyldopa
  • Metronidazole
• Causes of blue/green urine

  • Bacterial infections (urinary tract infection by Pseudomonas aeruginosa and intestinal tract infections, resulting in increased urinary indicant) indoxyl potassium sulfate
  • Ingestion of breath deodorizers (Clorets) can result in green urine.
  • Medications which may cause blue urine: Methocarbamol (Robaxin), Methylene blue, Amitriptyline (Elavil)
  • Phenol derivatives found in certain IV medications produce green or black urine on oxidation.
• Purple staining in catheter bags


  Caused by indican in the urine or a bacterial infection, frequently caused by Klebsiella or Providencia species