Urine Analysis Physical examination, interpretation and significance

In this article, we are going to discuss the Physical Examination of urine analysis with interpretation of every single piece of info in a urine analysis report .
We will discuss the Color, Aspect, Odour, PH and specific gravity with causes of change of each of them, interpretation and significance .

A- Color
• Normally it is amber yellow due to urochrome pigment which is a break down product of Hb related to bile pigments found in the urine.
Abnormal urine colors :
1. Colorless = polyurea
- D.M.        - D.I
- Compulsive H2O intake.

2. Reddish
- Haematuria.                   - Haemoglobinuria.
- Myoglobinuria. .            - Beetroot, Rhubarb.
- Drugs e.g. Rifampicin (orange-red).

3. Brownish
- Bilirubin.
- Flagyl.

4. Bluish      :    Amitriptyline (Tryptizole).
5. Greenish :   Pseudomonas
6. Blackish  :   Alkaptonuria .

.B- Aspect
• Cloudy or turbid urine provides a warning of possible abnormality as presence of pyuria, hematuria, excessive epithelial cells, excessive amorphous urate or mucus.

C- Odour
• Fruity or sweet odour may be present in cases of ketonuria.

D- PH  
(Normally acidic, pH= 5-7)

Causes of Alkaline urine 

- Renal tubular acidosis (kidney  tubules unable to excrete H+).
- Na HC03 or Na citrate intake. :,,
- High vegetable diet. i,
- Urinary tract infection with urea splitting organism e.g proteus .

Causes of Acidic urine 

- Normal urine .
- Ascorbic acid ( vit. C ) .
** Urine pH is unnecessary except in the diagnosis and treatment of renal tubular acidosis. It is also helpful in the treatment of renal stones.

E- Specific gravity
• Measurement of urine osmolality is more accurate.
• 1003 - 1025 (or more)
• After H2O deprivation for 12 hours it reaches 1025 or more.
• After plenty fluid intake it reaches 1003 or less.

Causes of Decreased specific gravity of urine 

 - Diabetes insipidus
 - Tubulointerstitial disease : Increased proteins ,,
- Compulsive H2O intake

Causes of Increased specific gravity of urine

- D.M
- Increased proteins .
- Volume depletion .
**NB: Urine specific gravity is a measure of the weight of dissolved particles in urine but osmolality reflects the number of such particles.
Urine Analysis Physical examination,  interpretation and significance
Dr.Tamer Mobarak


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