This document provides information about urine analysis including urine collection methods, macroscopic and microscopic examination of urine, chemical analysis of urine, and urine dipstick testing. Key points include: urine is formed in the kidneys by ultrafiltration of plasma; various urine samples are collected for different tests; macroscopic examination assesses urine volume, color, odor, pH, and specific gravity; chemical tests detect proteins, sugars, ketones, bilirubin and other substances; microscopic examination identifies cells, casts, crystals, and other particles in urine sediment; and urine dipsticks provide a convenient way to qualitatively assess multiple urine components.
8. Urinary volume
•Normal = 600-1550ml
•Polyuria- >2000ml
•Oliguria-<400ml
•Anuria-complete cessation of urine(<200ml)
•Nocturia-excretion of urine by a adult of >500ml
with a specific gravity of <1.018 at night
(characteristic of chronic glomerulonephritis)
12. Urinary pH/ reaction
•Reaction reflects ability of kidney to maintain
normal hydrogen ion concentration in plasma
& ECF
•Normal= 4.6-8
•Tested by- 1.litmus paper
2. pH paper
3. dipsticks
16. Specific gravity
•Depends on the concentration of various
solutes in the urine.
•Measured by-urinometer
- refractometer
- dipsticks
17. Urinometer
•Take 2/3 of urinometer container with urine
•Allow the urinometer to float into the urine
•Read the graduation at the lowest level of urinary
meniscus
•Correction of temperature & albumin is a must.
•Urinometer is calibrated at 15or 200c
So for every 3oc increase/decrease add/subtract
0.001
For 1gm/dl of albumin add0.001
20. Low specific gravity(hyposthenuria)
•All causes of polyuria except gycosuria
•Fixed specific gravity (isosthenuria)=1.010
Seen in chronic renal disease when kidney has
lost the ability to concentrate or dilute
22. Tests for proteins
•Test – HEAT & ACETIC ACID TEST
•Principle-proteins are denatured & coagulated on
heating to give white cloud precipitate.
•Method-take 2/3 of test tube with urine, heat only
the upper part keeping lower part as control.
•Presence of phosphates, carbonates, proteins gives a
white cloud formation. Add acetic acid 1-2 drops, if
the cloud persists it indicates it is protein(acetic acid
dissolves the carbonates/phosphates)
26. microalbuminuria
•The level of albumin protein produced by
microalbuminuria cannot be detected by urine
dipstick methods. In a properly functioning
body, albumin is not normally present in urine
because it is retained in the bloodstream by
the kidneys. Microalbuminuria is diagnosed
either from a 24-hour urine collection
27. Significance of microalbuminuria
•an indicator of subclinical cardiovascular disease
•an important prognostic marker for kidney disease
•in diabetes mellitus
•in hypertension
•increasing microalbuminuria during the first 48 hours
after admission to an intensive care unit predicts
elevated risk for acute respiratory failure , multiple
organ failure , and overall mortality
28. Bence Jones proteins
•These are light chain globulins seen in multiple
myeloma, macroglobulimias, lymphoma.
•Test- Thermal method(waterbath):
Proteins has unusual property of precipitating at 400
-600c & then dissolving when the urine is brought to
boiling(1000c) & reappears when the urine is
cooled.
29. Test for sugar
•Test-BENEDICT’S TEST(semiquantitative)
•Principle-benedict’s reagent contains cuso4.In the
presence of reducing sugars cupric ions are
converted to cuprous oxide which is hastened by
heating, to give the color.
•Method- take 5ml of benedict’s reagent in a test
tube, add 8drops of urine. Boil the mixture.
Blue-green= negative
Yellow-green=+(<0.5%)
Greenish yellow=++(0.5-1%)
Yellow=+++(1-2%)
Brick red=++++(>2%)
30. Benedict’s test
•Detects all reducing substances like glucose,
fructose, & other reducing sustances.
•To confirm it is glucose, dipsticks can be used
(glucose oxidase)
31. Causes of glycosuria
•Glycosuria with hyperglycaemia-
diabetes,acromegaly, cushing’s disease,
hyperthyroidism, drugs like corticosteroids.
•Glycosuria without hyperglycaemia- renal
tubular dysfunction
33. Rothera’s test
•Principle-acetone & acetoacetic acid react
with sodium nitroprusside in the presence of
alkali to produce purple colour.
•Method- take 5ml of urine in a test tube &
saturate it with ammonium sulphate. Then
add one crystal of sodium nitroprusside. Then
gently add 0.5ml of liquor ammonia along the
sides of the test tube.
•Change in colour indicates + test
37. Blood in urine
•Test- BENZIDINE TEST
•Principle-The peroxidase activity of hemoglobin
decomposes hydrogen peroxide releasing nascent
oxygen which in turn oxidizes benzidine to give blue
color.
•Method- mix 2ml of benzidine solution with 2ml of
hydrogen peroxide in a test tube. Take 2ml of urine &
add 2ml of above mixture. A blue color indicates +
reaction.
39. Type Plasma color Urine color
Hematuria normal Smoky red
m/s-plenty of
RBC’s
hemoglobunuria Pink,hepatoglob
in reduced
Red ,
occasional
RBC’s
Myoglobunuria Pink, normal
hepatoglobin
Red, occasional
RBC’s
40. Microscopic examination
•Microscopic urinalysis is done simply pouring the
urine sample into a test tube and centrifuging it
(spinning it down in a machine) for a few minutes.
The top liquid part (the supernatant) is discarded.
The solid part left in the bottom of the test tube (the
urine sediment) is mixed with the remaining drop of
urine in the test tube and one drop is analyzed under
a microscope
41. Contents of normal urine m/s
•Contains few epithelial cells, occasional RBC’s,
few crystals.
42. Crystals in urine
Crystals in acidic urine
Uric acid
Calcium oxalate
Cystine
Leucine
Crystals in alkaline urine
Ammonium magnesium
phosphates(triple
phosphate crystals)
Calcium carbonate
44. casts
•Urinary casts are cylindrical aggregations of
particles that form in the distal nephron,
dislodge, and pass into the urine. In urinalysis
they indicate kidney disease. They form via
precipitation of Tamm-Horsfall mucoprotein
which is secreted by renal tubule cells.
45. Types of casts
•Acellular casts
Hyaline casts
Granular casts
Waxy casts
Fatty casts
Pigment casts
Crystal casts
•Cellular casts
Red cell casts
White cell casts
Epithelial cell cast
46. Hyaline casts
•The most common type of cast, hyaline casts
are solidified Tamm-Horsfall mucoprotein
secreted from the tubular epithelial cells
•Seen in fever, strenuous exercise, damage to
the glomerular capillary
47.
48. Granular casts
•Granular casts can result either from the
breakdown of cellular casts or the inclusion of
aggregates of plasma proteins (e.g., albumin)
or immunoglobulin light chains
•indicative of chronic renal disease
49.
50. Waxy casts
•waxy casts suggest severe, longstanding
kidney disease such as renal failure(end stage
renal disease).
53. Fatty casts
•Formed by the breakdown of lipid-rich
epithelial cells, these are hyaline casts with
fat globule inclusions
They can be present in various disorders,
including
•nephrotic syndrome,
•diabetic or lupus nephropathy,
•Acute tubular necrosis
55. Pigment casts
•Formed by the adhesion of metabolic
breakdown products or drug pigments
•Pigments include those produced
endogenously, such as
•hemoglobin in hemolytic anemia,
•myoglobin in rhabdomyolysis, and
•bilirubin in liver disease.
56. Crystal casts
•Though crystallized urinary solutes, such as
oxalates, urates, or sulfonamides, may
become enmeshed within a hyaline cast
during its formation.
•The clinical significance of this occurrence is
not felt to be great.
57. Red cell casts
•The presence of red blood cells within the cast
is always pathologic, and is strongly indicative
of glomerular damage.
•They are usually associated with nephritic
syndromes.
63. Epithelial casts
•This cast is formed by inclusion or adhesion of
desquamated epithelial cells of the tubule
lining.
These can be seen in
•acute tubular necrosis and
•toxic ingestion, such as from mercury,
diethylene glycol, or salicylate.
64. Urine dipsticks
•Urine dipstick is a narrow plastic strip which has
several squares of different colors attached to it.
Each small square represents a component of the
test used to interpret urinalysis. The entire strip is
dipped in the urine sample and color changes in
each square are noted. The color change takes
place after several seconds to a few minutes from
dipping the strip. If read too early or too long after
the strip is dipped, the results may not be
accurate.
66. •The squares on the dipstick represent the
following components in the urine:
specific gravity (concentration of urine),
acidity of the urine (pH),
protein in the urine (mainly albumin),
glucose (sugar),
ketones
blood
bilirubin and
•urobilinogen
67. •The main advantage of dipsticks is that they
are
1. convenient,
2. easy to interpret,
3. and cost-effective
68. The main disadvantage is that the
1. Information may not be very accurate as the
test is time-sensitive.
2. It also provides limited information about the
urine as it is qualitative test and not a
quantitative test (for example, it does not give
a precise measure of the quantity of
abnormality).