This document discusses the examination of urine, including its typical composition, indications for urinalysis, and procedures for collecting and analyzing urine samples. Key points covered include the various substances measured in a urinalysis and their clinical significance, such as glucose, proteins, ketones, and cells. Methods for physical examination of urine properties like volume, color, odor and chemical tests are outlined. Preservation techniques and sources of contamination are also reviewed.

1. EXAMINATION OF URINE

2. COMPOSITION
o Volume
o Specific gravity
o Osmolality
o pH
o Glucose
o Proteins
o Urobilinogen
o Porphobilinogen
o Creatinine
o Sodium
o Urea nitrogen
o Uric acid
o Potassium
o Chloride
o Calcium
o Formiminoglutamic
acid
o Red cells, epithelial
cells, and white
blood cells

3. INDICATIONS FOR
URINALYSIS
1. Suspected renal diseases
2. Detection of urinary tract infection
3. Detection of Metabolic disorders
4. Detection of plasma cell dyscariasis
5. Diagnosis of Pregnancy

4. Collection of urine sample
• A single specimen: This may be a first
morning voiding, a random specimen, or a
post-prandial specimen.
• The first voided specimen in the morning
1. is the most concentrated and
2. has acidic pH in which formed elements
(cells and casts) are well preserved.

5. 1. This specimen is used for routine
examination,
2. fasting glucose,
3. proteins,
4. nitrite,
5. microscopic analysis for cellular
elements,
6. pregnancy test,
7. orthostatic proteinuria, and
8. bacteriological analysis.

6. • The random specimen is a single
specimen collected at any time of day. It is
used for routine urine examination.
• Post-prandial specimen (collected 2
hours after a meal in the afternoon) is
sometimes requested for estimation of
glucose (to monitor insulin therapy in
diabetes mellitus) or of urobilinogen.

7. 24-hour specimen: After getting up in the
morning, the first urine is discarded.
All the urine voided subsequently during the
rest of the day and the night is collected in a
large bottle (clean bottle of 2 liter capacity
with a cap).
The first urine after getting up in the morning
on the next day is also collected.

8. • The urine should be preserved at 4-6°C during
the period of collection.
• The container is then immediately transported
to the laboratory.
• The urine is thoroughly mixed and an aliquot is
used for testing.
• This method is used for quantitative estimation
of proteins and hormones.

9. COLLECTION METHODS
• Midstream specimen:
• Used for all types of examinations.
• After voiding initial half of urine into the toilet, a
part of urine is collected in the bottle.
• First half of stream serves to flush out
contaminating cells and microbes from urethra
and perineum.
• Subsequent stream is collected which is from
the urinary bladder.

10. • Clean-catch specimen:
• Recommended for bacteriologic culture.
• In men- glans penis is sufficiently exposed and
cleaned with soap and water.
• In women urethral opening should be exposed,
washed with soapy cotton balls, rinsed with
water-saturated cotton, and holding the labia
apart
• Initial urine allowed to pass and the remaining is
voided into the bottle (amount 20-100 ml).
• This method avoids contamination of urine with
the vaginal fluids.

11. • Catheter specimen:
• Bacteriological study or culture in
bedridden,
• Ill patients or in patients with obstruction of
urinary tract.
• Usually avoided in ambulatory patients-
bcz it carries the risk of introduction of
infection.

12. • Infants:
• A clean plastic bag can be attached around the
baby’s genitalia and left in place for some time.
• For bacteriologic examination, urine is aspirated
from bladder by passing a needle just above
symphysis pubis.

13. Changes -Standing Urine at
Room Temperature
1. Increase in pH
2. Formation of crystals
3. Loss of ketone bodies
4. Decrease in glucose
5. Oxidation of bilirubin to biliverdin
6. Oxidation of urobilinogen to urobilin
7. Bacterial proliferation
8. Disintegration of cellular elements

14. • Urine sample must be tested in the
laboratory within 2 hours of collection to
get the correct results.

15. Preservation of Urine Sample
• Can be kept in the refrigerator for a
maximum of 8 hours.
• Refrigeration (4-6°C)
• For routine urinalysis, preservatives
should be avoided, as they interfere with
reagent strip techniques and chemical test
for protein.

16. • Hydrochloric acid: used for preservation of a
24hour urine sample for adrenaline,
noradrenaline, vanillylmandelic acid, and
steroids.
• Toluene: It forms a thin layer over the surface
and acts as a physical barrier for bacteria and
air. It is used for measurement of chemicals.
• Boric acid: A general preservative.
• Thymol: It inhibits bacteria and fungi.
• Formalin: excellent chemical for preservation of
formed elements.

17. PHYSICAL EXAMINATION
1. Volume - only the 24-hr specimen of urine
needs to be measured and reported.
Adult average is 600-2000 ml.
2. Polyuria volume > 2000 ml/24 hours.
diabetes mellitus (osmotic diuresis),
diabetes insipidus (failure of secretion of
antidiuretic hormone), chronic renal
failure (loss of concentrating ability of
kidneys) or diuretic therapy.

18. • Oliguria - volume < 400 ml/24 hours.
Causes include febrile states, acute
glomerulonephritis (decreased glomerular
filtration), congestive cardiac failure or
dehydration (decreased renal blood flow).

19. • Anuria means urinary output < 100 ml/24
hours or complete cessation of urine
output. It occurs in acute tubular necrosis
(e.g. in shock, hemolytic transfusion
reaction), acute glomerulonephritis, and
complete urinary tract obstruction.

20. COLOR
• Normal urine color in a fresh state is pale
yellow or amber and is due to the
presence of various pigments collectively
called urochrome.
• Depending on the state of hydration urine
may normally be colorless (over hydration)
or dark yellow (dehydration).

21. • Colorless

22. Appearance
• Normal, freshly voided urine is clear in
appearance. Causes of cloudy or turbid
urine are listed in Table 1.3. Foamy urine
occurs in the presence of excess proteins
or bilirubin.

23. Odor
• Freshly voided urine has a typical aromatic
odor due to volatile organic acids. After
standing, urine develops ammoniacal odor
(formation of ammonia occurs when urea
is decomposed by bacteria).

24. • Some abnormal odors with associated
conditions are:
• Fruity: Ketoacidosis, starvation
• Mousy or musty: Phenylketonuria •
• Fishy: Urinary tract infection with Proteus,
tyrosinaemia.
• Ammoniacal: Urinary tract infection with
Escherichia coli, old standing urine.
• Foul: Urinary tract infection
• Sulfurous: Cystinuria.

25. Specific Gravity (SG)
• Normal SG of urine is 1.003 to 1.030
• SG increases as solute concentration
increases and decreases when
temperature rises

26. Reaction and pH
• The pH is the scale for measuring acidity
or alkalinity (acid if pH is < 7.0; alkaline if
pH is > 7.0; neutral if pH is

27. CHEMICAL EXAMINATION

28. • Normally, kidneys excrete scant amount
of protein in urine (up to 150 mg/24 hours).
• Proteinuria refers to protein excretion in
urine greater than 150 mg/24 hours in
adults.

29. Causes of Proteinuria

30. Tests for Detection of
Proteinuria
1. Heat and acetic acid test (Boiling test)
Principle: proteins get precipitated when
boiled in an acidic solution.

31. Reagent strip test:
Priniciple: “protein error of indicators”

32. • Sulphosalicylic acid test:
Addition of sulphosalicylic acid to the urine
causes formation of a white precipitate if
proteins are present

33. Quantitative Estimation of
Proteins
• Diagnosis of nephrotic syndrome
• Detection of microalbuminuria or early
diabetic nephropathy
• To follow response to therapy in renal
disease Proteinuria >1500 mg/ 24 hours
indicates glomerular disease;
• proteinuria >3500 mg/24 hours is called
as nephrotic range proteinuria; in tubular,
hemodynamic and post renal diseases,
proteinuria is usually < 1500 mg/ 24 hours.

34. Bence Jones Proteinuria
• Bence Jones proteins are monoclonal
immunoglobulin light chains (either κ or λ)
that are synthesized by neoplastic plasma
cells.

35. GLUCOSE
• The main indication for testing for glucose
in urine is detection of unsuspected
diabetes mellitus or follow-up of known
diabetic patients.
• Normally a very small amount of glucose
is excreted in urine (< 500 mg/24 hours or
<15 mg/dl) that cannot be detected by the
routine tests.

36. • Presence of detectable amounts of
glucose in urine is called as Glucosuria.

37. Causes of Glycosuria

38. Tests for Detection of Glucose
in Urine
Copper reduction methods:
Benedict’s qualitative test: When urine is
boiled in Benedict’s qualitative solution, blue
alkaline copper sulphate is reduced to red-
brown cuprous oxide if a reducing agent is
present.
But not specific for Glucose

39. Method
• Take 5 ml of Benedict’s qualitative reagent
in a test tube
• (composition of Benedict’s qualitative
reagent: copper sulphate 17.3 gram,
sodium carbonate 100 gram, sodium
citrate 173 gram, distilled water 1000 ml).
2. Add 0.5 ml (or 8 drops) of urine. Mix
well.
• 3. Boil over a flame for 2 minutes.
• 4. Allow to cool at room temperature.
• 5. Note the color change, if any.

40. • The result is reported in grades as follows Nil: no
change from blue color
• Trace: Green without precipitate
• 1+ (approx. 0.5 grams/dl): Green with
precipitate
• 2+ (approx. 1.0 grams/dl): Brown precipitate
• 3+ (approx. 1.5 grams/dl: Yellow-orange
precipitate
• 4+ ( > 2.0 grams/dl): Brick- red precipitate.

41. • Clinitest tablet method (Copper reduction
tablet test): This is a modified form of
Benedict’s test in which the reagents are
present in a tablet form (copper sulphate,
citric acid, sodium carbonate, and
anhydrous sodium hydroxide). Sensitivity
is 200 mgs/dl of glucose.

42. 2. Reagent strip method
• This test is specific for glucose and is
therefore preferred over Benedict’s test.

43. Ketones
• Excretion of ketone bodies (acetoacetic
acid, β-hydroxybutyric acid, and acetone)
in urine is called as ketonuria.
• Ketones are breakdown products of fatty
acids and their presence in urine is
indicative of excessive fatty acid
metabolism to provide energy.

44. Causes of Ketonuria
• Normally ketone bodies are not detectable in the
urine of healthy persons.
• If energy requirements cannot be met by
metabolism of glucose (due to defective
carbohydrate metabolism,
• low carbohydrate intake, or increased metabolic
needs),
• then energy is derived from breakdown of fats.
This leads to the formation of ketone bodies

45. 1. Decreased utilization of carbohydrates
2. Decreased availability of carbohydrates
in the diet.
3. Increased metabolic needs

46. Tests for Detection of Ketones in
Urine