Urine consists mainly of water with dissolved waste products like urea, uric acid, salts and other organic compounds. It is formed by ultrafiltration of blood in the kidneys, reabsorption of useful substances, and secretion of additional compounds. Urine analysis examines the specimen's physical characteristics like color, clarity and chemical components to screen for conditions like infections, kidney diseases and diabetes. Tests for glucose, proteins, ketones and other substances provide diagnostic information.

1. URINE EXAMINATION
Dr. Somendra Bansal
SMS Medical College, Jaipur

2. Urine
(96%)
water
Urine consists of:
Creatinine , uric acid
Inorganic:
Na+, K+,Cl-, Po4-,So4-
• Is an ultrafiltrate of plasma from which glucose, amino acids, water and
other substances essential to body metabolism have been reabsorbed
• Urine carries waste products and excess water out of the body.
(4%)
dissolved solids:
(2%)
Ureaalf)
(2%)
Other compounds
Organic:

3. 1.Ultrafiltration of plasma.
2.Reabsorption and secretion of various
substances.
3.Concentration of ultrafiltrate after which
it is called urine.

4. Collection of urinary specimens
• Males- mid stream urine sample
Chronic UTI- 4 aliquots of urine-VB1,VB2,EPS
VB3
• Females- mid stream
suspected infection- catheterise urine sample
• Neonates & infants- sterile plastic bag with an
adhesive collar over genitalia

5. Components of basic urinalysis
1.Specimen evaluation
2.Gross/physical examination
3.Chemical screening
4.Sediment examination

6. Specimen evaluation
• Collection of urine
– Early morning sample-qualitative
– Random sample- routine
– 24hrs sample- quantitative
– Midstream sample-UTI
– Post prandial sample-D.M

7. Changes occuring in standing urine
• Increase in Ph
• Formation of crystals
• Loss of ketone bodies
• Decrease in glucose
• Oxidation of bilirubin to biliverdin
• Oxidation of urobilinogen to urobilin
• Bacterial proliferation
• Disintegration of cellular elements

8. Preservatives in urine
• Most assays are performed on urine sample in 12-24h.
• Boric acid. A general preservative
• Hydrochloric acid. For preservation of 24hr urine sample
• Acetic acid.
• Toluene : for measurement of chemicals.
• Thymol : inhibits bacteria & fungi
• Formalin : preservation of formed elements

9. Physical Characteristics
Physical examination involves:
1.Color
2.Transparency
3.Odour
4.Volume
5. Specific gravity

10. Colour
• Influenced by fluid balance,
diet, medicines, and
diseases.
• Color intensity correlates to
concentration of urine.
• Normal : Pale yellow
(pigment urochrome)
• Colorless : Due to reduced
concentration.
• Cloudy/ milky :
Phosphaturia,Pyuria, Chyluria
• Red: Hematuria,hemoglobinuria,
myoglobinuria,beets, Rifampin,
phenolphthalein,
• Orange: dehydration,pyridium
• Green blue: Biliverdin,
Amitriptyline, Triamterene.
Methylene blue
• Brown: urobilinogen, porphyria
chloroquine, primaquine,
metronidazole, nitrofurantoin
• Brown-black:Alkaptonuria,
hemorrhage, melanin, methyldopa

11. Transparency
• Bacteria, blood, sperm, crystals, or mucus can
make urine look cloudy.
• Cloudy urine is most commanly due to
phosphaturia
• Other causes: pyuria, chyluria, lipiduria
• Thread-like cloudiness: Sample full of mucus.

12.  Chyluria - Lymph in urine. It is
associated with obstruction to
lymph flow and rupture of
lymphatic vessels into the renal
pelvis,ureters,bladder,or urethra.
causes – Filariasis, LN, Tumour
 Lipiduria- Fat globules
in the urine.eg-nephrotic
syndrome, fractures of
the major long bones or
pelvis.

13. • Normal urine have aromatic odour due to aromatic amino acid.
 Ammoniacal - long standing of urine due to decomposition of urea.
 fruity – diabetes mellitus due to presence of ketones
 isovaleric acidemia and glutaric acidemia - sweaty feet odor
 maple syrup urine disease-burnt sugar
 methionine malabsorption - cabbage odor
 Phenylketonuria - mousy odor
 Trimethylaminuria - rotting fish odor
 Tyrosinemia - Rancid odor
 Lack of odor in urine in ARF- suggest acute tubular necrosis.
Odour

14. Volume
• Is important part of assessment for fluid
balance and kidney functions.
• Adults produce from 600ml-2000ml / 24hr.
• For RUA, a 10ml-12ml of sample is optimal
for accurate analysis

15. URINE VOLUME
• Polyuria
 production of >2000ml of
urine in 24hr
 Causes
• diabetes mellitus
• diabetes insipidus
• polycystic kidney disease
• chronic renal failure
• Diuretics
• i/v saline/dextrose.
• Oliguria
 production of <500ml of urine in
24hr
 Causes
– PRE – RENAL : -hemorrhage,
prolong diarrhea and vomiting ,
severe burn. CHF, Sepsis,
anaphylaxis
– RENAL - interstitial nephritis ,
glomerulonephitis
– POST RENAL - bilateral
hydronephrosis, b/l ureteric calculi
, BPH.

16. Specific Gravity (SG)
SG - Measures the amount of substances dissolved
in urine.
– Higher SG : more solid material is dissolved in urine
– Low SG : excess fluid intake
• Urea , sodium chloride , sulfate, and phosphate
contribute most of the SG of normal urine.
• Reflects state of hydration & some idea of renal
concentrating ability
• Normal SG -1.016-1.022
• Isosthenuric: fixed SG at 1.010
• Normal Osmolality- 50-1200 mOsm/L

17. Methods to measure specific
gravity
1. Reagent strip
• Reagent area has 3 main ingredients : polyelectrolyte, indicator
substance and buffer.
– Principal is based on the pka change of pretreated polyelectrolytes
in relation to the ionic concentration of the urine.
2. Refractometer-it is based on refractive index of a solution and is
related to the content of dissolved solids present.
3. Urinometer.
4. Falling drop method.

18. • Take urinometer container filled
with urine 2/3rd of volume
• Allow the urinometer to float into
the urine
• Read the graduation at the lowest
level of urinary meniscus
• Urinometer is calibrated at 15or
200c
• Correction of temperature &
albumin is a must.
1. So for every 3oc
increase/decrease add/subtract
0.001
2. For 1gm/dl of albumin substract
0.003
3. For 1gm/dl of sugar substract
0.004

19. Chemical characteristics
• Glucose
• Bilirubin
• Ketone
• Blood
• Protein
• Urobilinogen
• Nitrite
• Leukocyte
• pH

20. Urine strip
• Strip is filter paper or plastic which has chemical
substance (reagent) coated on it on different pads.
• It gives color when react with substance in urine.
• The produced color is compared with chart color
visually or mechanically assessed.
Glucose
Bilirubin
Ketones
Specific Gravity
Blood
pH
Protein
Urobilinogen
Nitrite
Leukocyte

21. Strip include the tests:
• Glucose
• Bilirubin
• Ketone
• Specific Gravity
• Blood
• Protein
• Urobilinogen
• Nitrite
• Leukocyte
• pH

22. Results are reported as:
• In concentration (mg/dl)
• As small, moderate, or large
• Using the plus system (1+, 2+, 3+, 4+)
• As positive, negative, or normal
AutatedUrine Testing
Machine

23. • This method is rapid, easy, give early indication and is qualitative.
• Therefore, usually there are other confirmatory tests: (chemistry,
microbiology and microscopic analysis).
• Reaction in strip is effected by time, to reduce timing errors and to
limit variations in color interpretation; automated instrument is used
to read the reaction color on each test pad.

24. Proteins
• Healthy adults excretes- 80-150 mg/day
• Normal urine proteins- 30% albumin,30% globulin,
40% Tsu protein (Tamm-Horsfall)
• Microalbuminuria 30-300mg/day
– Is the presence of small amounts of albumin in urine.
– It is very important in detection of early stage of nephropathy and in diagnosis of DM complication
(nephropathy).
• minimal proteinuria <1.0gm/day
• moderate proteinuria 1.0-4gm/day
• heavy proteinuria >4gm/day

25. Causes of proteinuria:
• Glomerular (MC)- IgA nephropathy, DM
• Tubular- Fanconi syndrome
• Overflow- Multiple myeloma (Bence Jones )

27. • Qualitative test: using a dipstick impregnated with
tetrabromophenol blue dye.
• Minimal detectable protein concentration by this
method- 20-30 mg/dl
• False negative: alkaline urine, dilute urine, no albumin
• 3% sulfosalicylic acid: detect 15 mg/dl
• Quantitative test: 24 hr urinary collection ( if
qualitative testing reveal proteinuria)
• Plasma electrophoresis: Glomerular v/s tubular
• Immunoassay: Bence Jones protein

28. • Reagent strip is impregnated with tetrabromophenol blue
buffered to an acid pH of 3.
• In the absence of protein the strip is yellow
• 30-60sec following urine application, variable shades of green
develop, depending on the type and concentration of protein
present.

29. 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)

30. Sugar
Glucosuria: is the presence of abnormal conc. of glucose in
urine .
• Normally, glucose is reabsorbed by active transport in
proximal tubule and therefore doesn't appear in urine.
• If the blood glucose level exceeds the reabsorption capacity of
kidney tubules (renal threshold), glucose will appear in urine.
• Renal threshold of glucose: is around 180 mg/100 ml.

31. • Reagent strip is based on a specific glucose
oxidase and peroxidase method.a double
sequential enzyme reaction.in multistix-
potassium iodide chromogen –color changes
from blue to brown at 30 sec.and copper
reduction test.

32. Glucose + O2 Gluconic acid + H2O2
H2O2 + Chromogen Oxidized Chromogen + H2O
Glucose Oxidase
Peroxidase

33. 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.
• Detects all reducing substances like glucose, fructose, & other
reducing sustances.
• Method- take 5ml of benedict’s reagent in a test tube, add 8drops of
urine. Boil the mixture.

34.  Blue-green= negative
 Yellow-green=+(<0.5%)
 Greenish yellow=++(0.5-
1%)
 Yellow=+++(1-2%)
 Brick red=++++(>2%)
 To confirm it is glucose, dipsticks
can be used (glucose oxidase)

35. KETONES
ketonuria: is the presence of abnormal amount of ketone bodies
in urine.
• Body normally uses carbohydrates as source of energy.
• If carbohydrate source depleted or there is defect in
carbohydrate metabolism, body use fat as a source of energy.
Fatty acid utilization occurs incompletely and results in
production of intermediate substances (ketone bodies).
• Three ketone bodies: acetone, acetoacetate, b-hydroxybutyric
acid

36. • Elevated levels of ketone bodies in blood and urine cause
acidosis which leads to coma and death.
• Ketonuria present in:
Diabetic ketoacidosis
During pregnancy
After period of starvation or rapid weight reduction
Ketonuria is common in uncontrolled DM
• because diabetic patient has high blood glucose but can't use
by cells, so lipids are used as source of energy.

37. Rothera’s test
• Principe-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.

38. • Reagent strip contains buffers and sodium
nitroferricyanide which react with acetoacetic
acid, producing a pink –maroon color
• False positive:- acidic urine of high SG,
levodopa metabolites in urine

39. Blood
Hematuria:- Presence of blood in the urine.
• Visible/Gross Hematuria:- symptom
tea-colored, cola-colored, pink or even red
• Nonvisible/Microscopic:- sign
normal colour with eyes

40. Hemoglobinuria:
• Presence of hemoglobin in urine due to rupturing of RBCs
• occur in malaria, typhoid, yellow fever, hemolytic jaundice
and other diseases.

41. • A positive dipstick for blood in urine:
hematuria,hemoglobinuria or myoglobinuria
• Chemical detection of blood in urine is based on peroxidase
like activity of hemoglobin.
• Microscopic examination of centrifuged urine
Erythrocytes present:-hematuria
Erythrocytes absent:-serum examination
Hemoglobinuria-supernatant pink
Myoglobinuria-serum clear

42. Causes of False-positive
dipstick readings
• Contamination of urine specimen with menstrual blood
• Dehydration-high specific gravity
• First morning voided specimen-high specific gravity
• Exercise
• Semen is present in the urine after ejaculation
• An alkaline urine with a pH >9 or contamination with
oxidizing agents used to clean the perineum.
• The presence of myoglobinuria

43. Extraglomerular Glomerular
Color (if macroscopic) Red or pink
Red, smoky brown, or
"Coca-Cola"
Clots May be present Absent
Proteinuria <500 mg/day May be >500 mg/day
RBC morphology Normal Dysmorphic
RBC casts Absent May be present

44. 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.

45. Bilirubin
• It is breakdown product of hemoglobin that is formed
RE cells of the spleen, liver and bone marrow.
• It is based on coupling reaction of bilirubin /
urobilinogen with a diazonium salt in acid medium
and color change from cream buff to tan at 20 sec.
• False negative: ascorbic acid
• False positive: phenazopyridine

46. Bilirubin + Glucuronic Acid
Conjugated Bilirubin (LMW) – Water Soluble
From liver to intestine
Urobilinogen
50 % Excreted in
Stool
50 % Reabsorbed into enterohepatic
circulation. A small amount of absorbed
urobilinogen(1-4 mg/day )will escape
hepatic uptake & be excreted in urine.

47. • Normal urine contain no bilirubin, only small
amount of urobilinogen
• Conjugated Bb not appear in urine except in
pathological condition (intrinsic hepatic ds/
bile duct obstruction)
• Indirect Bb (HMW) bound to albumin, water
insoluble & therrefore not appear in urine
even in pathological condition.

48. • Hemolysis & hepatocellular ds.-increase bile
pigment-increase urinary urobilinogen
• Bile duct obstruction/antibiotic coverage-
decrease urobilinogen

49. Nitrite
• Presence of nitrites in urine strongly suggestive of bacteriuria.
• Normal urine contain nitrate but not contain nitrites.
• In the presence of bacteria, the normally present nitrate in the urine
is reduced to nitrite.
• Multistix is impregnated with p-arsanilic acid,which forms a
diazonium salt. When it react with nitrite present in the urine this
compound is then able to couple with benzoquinoline to form a pink
azo dye.
• Positive test indicates presence of more than 10 organisms/ml.
reductionnitrate nitrite "pink"

50. Leucocyte esterase
• LE activity indicates presence of WBC in urine
• Depends on esterase method:
+ve result: means more than 5 leucocytes/hpf. (high power field) intensity of
the color produced is proportional to the amount of enzyme present,which
is related to the number of neutrophils present.
If urine stands for long time, leucocytes lyse and more intense reaction occur.
• False positives: specimen contamination
• False negative: large amounts of oxalic acid can inhibit the reaction, increase
SG, glycosuria, urobilinogen, ascorbic acid
Esterase + Ester 3-0H-5-phenyl pyrrole diazonium salt
pink -purple color
neutrophils reagent
strip

51. pH
• Normal urine pH: 4.5-8 (average: 5.5-6.5)
acidic: 4.5-5.5 & alkaline: 6.5-8
• Urine pH reflects ph in serum exception- RTA
• Inability to acidify urine <5.5 ph after administration of an acid load is
diagnostic of RTA
• Urine sample must be fresh : on standing urine become alkaline as a
result of ammonia liberation due to urea decomposition
• Dipsticks-indicators methyl red and bromothymol blue give a range of
orange,green and blue colors as pH rises.

52. • Acidic urine
– Ketosis-diabetes,
starvation, fever
– Systemic acidosis
– UTI- E.coli
– Acidification therapy
• Alkaline urine
– Strict vegetarian
– Systemic alkalosis
– UTI- Proteus
– Alkalization therapy

53. Urinary sediment
• First morning urine specimen is specimen of
choice & should be examined with in 1 hrs.
• 10-15 ml urine should be centifuged for 5
minutes at 3000 rpm.
• Ideal volume of fluid deposited on slide- 0.01-
0.02 ml

54. • Urinary sediment should be examined
microscopically for-
Cells, cast, crystals, bacteria, yeast, parasites
• Low-power(x100)- RBC,WBC,cast,cystine
crystals,oval fat macrophage,parasites
• High-power(x400)-d/d circular & dysmorphic
RBC, identify bacteria and yeast

55. • Circular RBC- even distribution of Hb
• Dysmorphic RBC- irregular shape
• Old leukocytes- small & wrinkled appearance
• Fresh leukocytes- generally indicate urinary
tract pathology ( Glitter cells)
• Renal tubular cells- renal pathology

56. • Tamm-Horsfall mucoprotein- basic matrix of all renal casts,it
originates from tubular epithelial cells & always + in urine
• Hyaline cast- contain only mucoprotein
• RBC cast- Glomerular bleeding
• WBC cast- AGN,APN,ATIN
• Granular & waxy cast-further degeneration of cellular
elements
• Broad cast- CRF
• Fatty cast-nephrotic syndrome, hypothyroidism,lipiduria