Physical Examination of Urine

Physical Examination of Urine

• Urine analysis includes assessment of color, clarity, and specific gravity.
• Historical reliance on urine characteristics for medical decisions highlights their diagnostic value.
• Color and clarity of urine provide essential clues to potential disorders such as:
  • Glomerular bleeding
  • Liver disease
  • Inborn metabolic errors
  • Urinary tract infections
• Specific gravity measurement evaluates renal tubular function and helps in diagnosing kidney-related issues.
• Physical examination results may clarify and support chemical and microscopic analysis findings.

Key Learning Objectives

• Identify common terminology used to describe normal urine color.
• Understand the role of urochrome in influencing urine color.
• Recognize the clinical importance of urine clarity and its implications.
• Differentiate between causes of cloudy urine:
  • Pathologic causes (e.g., infections, inflammation)
  • Nonpathologic causes (e.g., dietary factors, dehydration)

Specific Gravity

• Definition: Measurement indicating urine concentration relative to water.
• Significance: Evaluates kidney concentrating ability; aids in diagnosing various renal conditions.
• Methods for measuring specific gravity include:
  • Urinometer: uses buoyancy principles to measure density.
  • Refractometer: measures the refractive index of urine.
  • Harmonic oscillation densitometry: uses sound waves to determine density.

Adjustments for High-Molecular-Weight Substances

• The presence of glucose and protein in urine can affect specific gravity readings.
• Ability to calculate needed corrections for accurate measurement when high-molecular-weight substances are present.

Abnormal Urine Odor

• Understanding possible causes of abnormal urine odor can provide diagnostic insights and further investigation into underlying health issues.