Indications for Urine examination include: Suspected renal damage Detection of UTI Management of metabolic disorders Diagnosis of jaundice Management of Plasma cell dyscrasias Diagnosis of pregnancy Drug abuse Physical Examination of Urine includes estimation of Appearance, Volume, Colour, Odour, reaction, Specific gravity and Osmolality.

1. PHYSICAL EXAMINATION OF
URINE
By: Dr. Deepa Anantha Laxmi N.V
Department of Pathology
MIMS

2. FORMATION OF URINE
• In the normal adult,
approximately 1200 mL of
blood perfuses the kidney
each minute, which
accounts for about 25% of
the cardiac output.
• 180 L in 24 hours is
reduced to about 1 to 2 L

3. INDICATIONS OF URINE EXAMINATION
• Suspected renal damage
• Detection of UTI
• Management of metabolic disorders
• Diagnosis of jaundice
• Management of Plasma cell dyscrasias
• Diagnosis of pregnancy
• Drug abuse

5. SAMPLE TYPE SAMPLING USE
Random specimen No specific time
most common, taken
anytime of day
Routine screening, chemical
& FEME (Full and microscopy)
Morning sample First urine in the morning,
most concentrated
Pregnancy test, microscopic
Test, Nitrates, Orthostatic
proteinuria
Clean catch midstream Discard first few ml, collect
the rest
Culture
24 hours All the urine passed during
the day and night and next
day Ist sample is collected.
Used for quantitative and
qualitative analysis of
Substances (Protein, VMA,
Catecholamines, metanephrines,
hormones )
Postprandial 2 hours after meal Diabetic glucosuria monitoring

6. TYPES OF COLLECTION
: Flushes the contaminants and microbes of
urethra and perineum.
: Bacterial culture
: Bedridden patient
: Commercially available for babies
: Bacteriology
: Prostatic infection
2=3 = UTI
2<3= PROSTATIC INFECTION

8. STORED URINE
• Decreased Clarity (Bacterial proliferation)
• Odour- Ammonaical
• Increased Ph: Due to ammonia
• Prescipitation of Crystals
• Loss of ketone bodies (Volatility)
• Decreased Glucose (Glycolysis)
• Oxidation of Bilirubin  Biliverdin (False negative)
• Oxidation of Urbilinogen  Urobilin
• Disintegration of Cellular elements

9. PRESERVATION OF URINE SAMPLE
• Ideal : Examine within 2 hrs
• Preservation methods: 1. Refrigeration 2. Chemical Preservation
• 1. Refrigeration:
• Delay: Refrigerate for maximum of 24 hours (4-6 0c)
• Refrigeration raises Specific gravity
• Warm to room temperature before examination

10. PRESERVATION OF URINE SAMPLE
• 2. Chemical preservation
• Avoid for routine
• Interferes with Reagent strips and chemical tests
• A. HCL: (10 ml of 6N Hcl)
• Adrenaline, Noradrenaline, VMA, Steroids
• B. Toulene (2ml/ 100ml urine)
• Forms a barrier
• Preserves proteins, reducing substances and ketones

11. PRESERVATION OF URINE SAMPLE
• 2. Chemical preservation
• C. Boric acid (0.8%)
• Prevents bacterial growth
• Preserves proteins and formed elements
• D. Thymol: (1 small crystal/ 100ml)
• Inhibits bacteria
• Preserves cellular elements and glucose. Interferes with acid prescipitation
• E. Formalin:
• Excellent for formed elements
• Interferes with chemical analysis

12. PRESERVATION OF URINE SAMPLE
• 2. Chemical preservation
• F. Sodium carbonate:
• Qualitative analysis of Porphyrins and porphobilinogen.
• Unacceptable for routine
• G. Commercial preservative tablet (1 tab/30ml)
• Releases formaldehyde

13. PHYSICAL EXAMINIATION OF URINE
1. Volume
2. Appearance
3. Colour
4. Odour
5. Reaction
6. Specific gravity
7. Osmolality

14. VOLUME/ QUANTITY OF URINE
• Majorly determined by the water intake
• Normal : 600-2000 ml/ 24 hours
• Night time: 400ml
• Pregnancy there may be reversal
• Young children excrete 2-3 times more urine / kgbwt than adults

15. VOLUME/ QUANTITY OF URINE
• POLYURIA: >2000 ml/ 24 hours
• Nocturia: > 500ml
• Higher volume of urine usually has lesser specific gravity
• Causes of polyuria may be
• 1. Physiological:
• Polydipsia, IV fluid, Excess salt and protein diet
• 2. Pathological

16. VOLUME/ QUANTITY OF URINE
PATHOLOGICAL INCREASE IN
VOLUME
a) Diabetes mellitusa) Renal tubular defect
b) Diuretics
c) Sodium wasting
d) Impaired counter current multiplier
e) Progressively produce isotonic urine
DIABETES INSIPIDUS
a. Central DI
b. Nephrogenic DI
III. OSMOTIC DIURESIS
II. DEFECTIVE RENAL WATER & SALT
ABSORBTION
I. DEFECTIVE HORMONE REGULATION

17. VOLUME/ QUANTITY OF URINE
• OLIGURIA: <500ml/ 24 hours
• Dehydration
• Fever
• Acute glomerulonephritis
• Bilateral hydronephrosis
• Acute tubular necrosis
• ANURIA: <150ml/ 24 hours to total absence
• Shock
• Acute tubular necrosis
• ESRD

18. APPEARANCE/ CLARITY/ CHARACTER
• Normal: Clear
• Cloudy: Difficult to read newsprint
• Turbid: Cannot read newsprint
• Causes of Turbidity:
1. Bacterial proliferation (removed by acidification)
2. Phosphates (removed by adding acetic acid)
3. Urates (Removed by heating)
4. Antiseptics

19. APPEARANCE/ CLARITY/ CHARACTER
5. Genital, fecal discharge (fistula), menstrual contamination.
6. RBC, Sperms, Prostatic fluid, epithelial debris
7. Chyluria : (Removed by chrloroform)
• Lymph in urine
• Ruptured lymphatics
• Layer of chilomicrons on top
• Wichereria bancrofti
• Pseudochyluria: Vaginal cream, urates, Candida.

20. APPEARANCE/ CLARITY/ CHARACTER
8. Lipiduria:
• Nephrotic syndrome
• Skeletal injury
• Major orthopaedic surgery
• Confirmation: Oil red O/ Polarization of cholesterol

22. COLOUR
• Colour of urine is largely due to Urochrome and Urobilin; and smaller
amount of Uro-erythrin
• Increased in fever, thyrotoxicosis, starvation, dehydration .etc.
1. RED
2. YELLOW BROWN-GREEN BROWN
3. ORANGE RED TO ORANGE BROWN
4. DARK BRONW-BLACK
5. BLUE GREEN

23. COLOUR
• 1. RED COLOUR:
• Rule out beet root consumption and take drug history
• Menstrual contamination
• Porphyrias: Congenital erythroporphyria, porphyria cutanea tarda
• Lead porphyria : Normal colour
• Hematuria, hemoglobinuria, myoglobinuria- reagent strips
• Acute intermittent porphyria darkens on standing
• Unstable haemoglobin: Dipyrrole, bisulfan

24. COLOUR
• 2. YELLOW BROWN- GREEN BROWN:
• Bile pigment (Bilirubin)
SHAKE
WHITE FROTH
CONCENTRATED URINE
YELLOW FROTH
BILIRUBIN

25. COLOUR
• 3. ORANGE RED TO ORANGE BROWN:
• Obstructive Jaundice
• Urobilinogen-----------------Urobilin
Pitfall alert: Urobilin does not produce Yellow froth

26. COLOUR
• 4. DARK BROWN OR BLACK
• Hemogentisic acid excretion : Alkaptonuria- Darkens more rapidly when
alkaline
• Melanin
• Hemoglobin Methemoglobin
• Cola coloured: Rhabdomyolysis, Oral L-Dopa

27. COLOUR
• BLUE/ BLUE GREEN:
• Intake of food additives
• Drugs like amitriptyline, cimetidine, Phenergan, sildenafil
• Pseudomonas infection
• Methylene blue

28. ODOUR
• Normally has faint aromatic odour
• Cystinuria: Rotten eggs
• Hawkinsinuria: Swimming pool
• Ketoacidosis: Sweet, fruity
• Isovaleric acidemia and glutaric
academia: Sweaty feet
• Maple syrup urine disease (MSUD):
Maple syrup
• Methionine malabsorption: Cabbage, hops
• Phenylketonuria: Mousy, musty
• Trimethylaminuria: Rotting fish
• Tyrosinemia: Rancid
Lack of smell ATN in renal disease

29. REACTION/ pH
• Normal: 4.6- 8.0
• By: Litmus paper, Nitrazine paper, Ph strip

30. pH
• Kidneys play a role in maintaining acid-base balance
• Helps identify defects in renal tubular secretion or reabsorption of
acids and bases
• Use to modify diet / manage disease in metabolic disroders
• Helps identify crystals or determine if specimen is satisfactory
• First morning specimen is usually slightly acidic (5.0-6.0)
• pH tends to be more alkaline after a meal (alkaline tide)
• Double indicator system: Methyl red and bromothymol blue

32. SPECIFIC GRAVITY
• Urea (20%), sodium chloride (25%), sulfate, and phosphate contribute most of
the specific gravity of normal urine.
• Normal urine Specific gravity is 1.003 to 1.030.
• Methods :
1. Reagent strip,
2. Refractometer,
3. Urinometer, &
4. Falling drop method.

33. SPECIFIC GRAVITY
• 1. REAGENT STRIP METHOD:
• Indirect method
• Three main ingredients present
1. Polyelectrolyte,
2. Indicator substance, and
3. Buffer
• Principle
• Pka change of pre-treated polyelectrolytes in relation to the ionic
concentration of the urine.
• When the ionic concentration is high, the Pka (acid dissociation constant) is
decreased, as is the pH

34. SPECIFIC GRAVITY
• 2. REFRACTOMETER METHOD
• Also an indirect method
• The refractive index is the ratio of the velocity of light in air
to the velocity of light in a solution
• The specific gravity reading on the refractometer is generally
slightly lower than a urinometer reading on the same urine
specimen by about 0.002.

35. SPECIFIC GRAVITY
• 3. URINOMETER METHOD: Squibb’s Urinometer
• Directly measures the specific gravity at room temperature
• Calibrated with distilled water at 1.000
• Correction for temperature: 0.001 for every 30
• Correction for Proteins : subtract 0.003 for every gram
• Correction for Glucose: subtract 0.004 for every gram

36. SPECIFIC GRAVITY
• Procedure for Squibb’s Urinometer:
• The urinometer vessel is filled till about 15 mL. (Total capacity 25ml)
• Inserted with a spinning motion

37. SPECIFIC GRAVITY
• 4. Falling drop method:
• direct method for measuring specific Gravity
• more accurate than the refractometer
• is more precise than the urinometer
• A measured drop of urine is introduced into the column, and as this
drop falls, it encounters two beams of light;
• Breaking the first beam starts a timer, and breaking the second turns
it off
• Reading is electronically measured

38. • ISOTHENURIA • HYPOSTHENURIC • HYPERSTHENURIC
• S.G. is fixed at 1.010 • Low S.G. • High S.G
• Indicates no concentrating
and diluting ability of
tubules and severe renal
damage
• Diabetes insipidus
• Reduction of tubular
concentrating ability
• Adrenal insufficiency
• Hepatic disease
• Congesting heart failure
Excess water loss
(vomiting, diarrhoea,
sweating)

39. Osmolality
• Number of particles of solute per unit of solution
• The normal adult with a normal fluid intake will produce urine of
about 500 to 850 mOsm/kg water
• 40 to 80 mOsm/kg water during water diuresis
• 800 to 1400 mOsm/kg water in dehydration
• The freezing-point depression method is commonly employed.

41. Sources
• Henry’s Clinical Diagnosis and Management By Laboratory Methods
• Online resources