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Biochemistry Reviewer
Urinalysis: Composition, Examination, and Abnormalities
For Dentistry
WHAT IS URINE?
Urine is the fluid secreted by the kidneys, transported via ureters, stored in the bladder, and
voided through the urethra.
• Normal urine is clear, straw-colored, slightly acidic, and has the odor of urea.
• Specific gravity ranges from 1.003 to 1.035.
• Normal constituents include water, urea, sodium chloride, potassium chloride,
phosphates, uric acid, organic salts, and urobilin pigment.
• Abnormal constituents indicating disease include ketone bodies, protein, bacteria, blood,
glucose, pus, and certain crystals.
• Normal urine volume: about 1-2 liters per day, varying with fluid intake, stress, and
illness.
• Urine color varies with diet and concentration; more water intake generally dilutes urine
making it lighter.
URINE COLLECTION
• Use a clean glass or plastic container.
• Morning (overnight) urine sample is best.
• If not processed within an hour, preserve by refrigeration or adding a few drops of
formalin or toluene.
URINE EXAMINATION
1. Physical Examination
2. Chemical Examination
3. Microscopic Examination
PHYSICAL EXAMINATION
Color:
• Normal: yellow to amber
• Blood present: brown to red
• Bile present: produces yellow foam
Transparency:
• Normal urine is clear, not cloudy.
Odor:
