Urine Analysis
1- Physical Examination
2- Chemical Examination
3- Microscopic Examination
4- Microbiological Examination
Urine Analysis
Collection of Urine for
Analysis
• Urine is collected over a period of 24
hours.
• A preservative (as toluene, chloroform,
thymol & formalin) is added to prevent
contamination of the urine
• keeping urine in refrigerator is greatly
advisable especially in hot weather.
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URINE ANALYSIS
Physical Examination
1- Volume
2- Specific Gravity
3- Aspect
4- Color
5- Odor
6- Deposit
7- Reaction (pH)
URINE ANALYSIS
Physical Examination
1- Volume:
Normal urine volume in 24 hours is 600-2000 ml
1- Urine volume increases (Polyuria) in the following conditions:
Physiological:
 Increased fluid intake
 Diuretic
Pathological:
 Diabetes mellitus (type-1 & type-2)
 Diabetes insipidus (due to decrease of ADH)
 Chronic renal failure
2- Urine volume decreases (Oliguria or anuria) in the following
conditions:
 Dehydration
 Acute renal failure
 Obstruction
URINE ANALYSIS
Physical Examination
2- Specific gravity (SG):
• Specific gravity measures solute concentration (urea
and sodium).
• Normally the specific gravity ranges between
1.015-1.025.
1- Increased in
• Dehydration (with oliguria)
• Diabetes Mellitus (with polyuria)
• Acute renal failure (with oliguria)
2- Decreased in
• Diabetes insipidus (with polyuria)
URINE ANALYSIS
Physical Examination
3- Appearance:
Normal fresh urine: clear (transparent)
Abnormal : Cloudy urine
may indicate possible abnormal constituents
such as white cells, epithelial cells, crystals and
bacteria.
N.B. Stored urine with no preservative & no cooling
may turn clear urine samples into cloudy.
URINE ANALYSIS
Physical Examination
4- Color:
Normal color: pale yellow (amber yellow)
due to the presence of pigments of urobilin or
urobilinogen
Abnormal colors of urine:
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Colorless
Orange
Greenish yellow
Red
Black
Smoky
URINE ANALYSIS
Physical Examination
Color (cont.)
1- Colorless Urine:
 Chronic renal failure
 Diabetes insipidus.
2- Orange Urine:
 Ingestion of large amount of carotenoids (vitamin A)
3- Yellowish brown urine:
due to presence of billirubin in cases of:
• Obstructive Jaundice
• Hepatic Jaundice
URINE ANALYSIS
Physical Examination
Color (cont.)
4- Red urine:
due to presence of blood, hemoglobin & RBCs.
5- Black urine:
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Methemoglobin
Homogentisic acid in alkaptonuria
Malignant malaria (black water fever due to Malaria
falciparum).
Melanin (melanoma)
6- Smoky urine:
• presence RBCs. in the urine, in cases of
acute glomerulonephritis
URINE ANALYSIS
Physical Examination
5- Odor:
Normal Urineferous odor:
The normal odor of fresh voided urine sample
Abnormal Odors
1- Fruity odor
due to presence of acetone in the urine as in diabetic
ketoacidosis
2- Ammonia odor
due to release of ammonia as result of:
the bacterial action on urea in the contaminated urine
or long standing exposed urine samples.
URINE ANALYSIS
Physical Examination
6- Deposits:
• Normally the urine is devoid of deposits.
• The presence of deposits is mainly due to
various types of crystals, salts and cells.
URINE ANALYSIS
Physical Examination
7- Reaction (pH):
Normally: The pH of urine varies from 4.6 - 8.0
1- Acidic urine:
• Large intake of meat & certain fruits (cranberries)
• Metabolic & respiratory acidosis
2- Alkaline urine:
• Vegetarians
• Metabolic & respiratory alkalosis
• Urinary tract infection by urea splitting bacteria which
split urea to ammonia (alkaline)
URINE ANALYSIS
Chemical Examination
Normal Constituents of Urine
Normal urine contains about 50g of solids dissolved in about 1.5 liters of water per day.
Urine contains organic and inorganic solids.
A) Chief Inorganic Solids
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Sodium, potassium & chlorides
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Smaller amounts of calcium, magnesium, sulfate & phosphates
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Traces of iron, copper, zinc and iodine.
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B) Chief Organic Solids:
1- Non-protein nitrogen:
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amino acids, ammonia, urea, uric acid , creatine & creatinine
2- Organic acids:
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lactic acid, citric acid & oxalic acid
ketone bodies (few amounts)
3- Sugars:
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Normally not more than 1g of sugars is excreted in the urine per day.
Sugars cannot be detected by ordinary tests.
Very small amounts of glucose not exceeding 150 mg of glucose are normally excreted per
day.
Other sugars present in urine are: pentose and lactose .
Lactosuria occurs in infant and in women during the late months of pregnancy and during
lactation
URINE ANALYSIS
Chemical Examination
Abnormal Constituents of Urine
1- Proteins (proteinuria)
2- Sugars (glucosuria, fructosuria &
galactosuria)
3- ketone Bodies (ketonuria)
4- Billirubin (billirubinuria) & Bile Salts
5- Nitrites
URINE ANALYSIS
Chemical Examination
1- Proteins: (proteinuria)
Proteinuria
Presence of more than 150 mg proteins in urine
in 24 hours detected by ordinary laboratory
means
heavy proteinuria :
＞4 gm/24 hours
moderate proteinuria: 1 - 4 gm/24 hours
minimal proteinuria: ＜ 1.0 gm/24 hours
URINE ANALYSIS
Chemical Examination
1- Proteins: (proteinuria)
Proteinuria is divided into prerenal, renal and postrenal proteinuria.
1-Prerenal proteinuria:
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Bence-Jones protein: This abnormal gamma globulin (light chains only) is
synthesized by malignant plasma cells (multiple myeloma).
It precipitates at 60oC, redidssolves at 100oC and reprecipitates on
cooling.
2-Renal proteinuria:
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Severe muscular exercise
After prolonged standing
Acute glomerulonephritis
Nephrotic syndrome
3- Postrenal proteinuria:
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Lower urinary tract inflammation, tumors or stones.
URINE ANALYSIS
Chemical Examination
2- Sugars: (glycosuria)
Glucose (Glucosuria);
Presence of detectable amount of glucose in urine which occurs in the
following conditions:
- Uncontrolled Diabetes Mellitus (DM)
- Renal glucosuria with lowering of renal threshold : e.g. during pregnancy
(gestational diabetes).
Fructose (Fructosuria):
Presence of fructose in urine & may be due to:
- Alimentary causes following the ingestion of large amounts of fructose
Fructosemia & herditary fructose intolerance (Metabolic disorders of
fructose).
Galactose (Galactosuria):
Presence of galactose in urine& may be due to:
- Alimentary causes following the ingestion of large amount of galactose.
- Galactosemia
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URINE ANALYSIS
Chemical Examination
3- Ketone Bodies (Ketonuria):
Presence of acetone, acetoacetic acid and
β hydroxybutyric acid in urine due to:
• Diabetic ketoacidosis (uncontrolled DM)
• Starvation
• Unbalanced diet: high fat & low carbohydrates
diet.
URINE ANALYSIS
Chemical Examination
4- Bilirubin (bilirubinuria)
Billirubin appears in urine in cases of:
• Hepatocellular Jaundice:
as in viral hepatitis
• Obstructive Jaundice
as any cause of obstruction of bile duct
URINE ANALYSIS
Chemical Examination
5- Nitrites
• In bacteruria in urine (in cases of
Urinary Tract Infection, UTI)
MICROSCOPIC URINE EXAMINATION
• Specimen of Choice:
First morning , midstream, clean catch urine specimen.
This specimen is preferred since it is most concentrated and
thus small amounts of abnormal constituents are more likely
to be detected
• Procedure:
1- By pouring the urine sample into a test tube &
centrifuging it (spinning it down in a machine) for a few
minutes.
2- The top liquid part (the supernatant) is discarded.
3- 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.
MICROSCOPIC URINE EXAMINATION
Urine is examined microscopically for:
1234.
Cells
Casts
Crystals
Parasitic ova
MICROSCOPIC URINE EXAMINATION
Cells
Red Blood Cells (RBCs)
Normally: < 3 RBCs / HPF
Hematuria
is the presence of abnormal numbers of red cells in urine
Types of Hematuria:
1- Gross hematuria
Means that the blood can be seen by the naked eye.
The urine may look pink, brown or bright red.
2- Microscopic hematuria
Means that the urine is clear, but blood cells can
be seen when urine is examined under microscope.
Causes of hematuria:
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Glomerular damage : as in acute glomerulonephritis
Tumors
Urinary tract stones
Upper & lower urinary tract infections
MICROSCOPIC URINE EXAMINATION
Cells
White Blood Cells (WBCs)
Normally : WBCs: < 5 cells / HPF
Pyuria (Pus in Urine)
Refers to the presence of abnormal numbers of WBCs that may
appear with:
- Urinary tract Infection : upper or lower
- Acute glomerulonephritis
- Acute pyelonephritis
Repeated sterile cultures in presence of pyuria may indicate:
-The patient is on antibiotic therapy
-The presence of an organism that does not grow on
ordinary media as T.B.
-Non- bacterial urethritis or cystitis as viral infection
MICROSCOPIC URINE EXAMINATION
Cells
Epithelial Cells
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Renal tubular epithelial cells contain a large round or oval
nucleus & normally slough into the urine in small numbers.
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The number sloughed renal epithelial cells is increased in:
- Nephrotic syndrome (Glomerular)
- Renal tubular degeneration (Tubular)
MICROSCOPIC URINE EXAMINATION
Casts
Urinary casts are formed only in the distal convoluted tubule
(DCT) or the collecting duct.
Types of Casts
Acellular casts
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Hyaline casts
Granular casts
Waxy casts
Fatty casts
Pigment casts
Crystal casts
Cellular casts
• Red cell casts
• White cell casts
• Epithelial cell cast
MICROSCOPIC URINE EXAMINATION
Casts
Hyaline casts
• Hyaline casts
composed of a mucoprotein (Tamm- Horsfall protein)
secreted by tubular cells.
MICROSCOPIC URINE EXAMINATION
Casts
Hyaline casts cont.
Hyaline casts cont.
The factors which favor protein cast formation are:
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Low flow rate
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High salt concentration
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Low pH
All of which favor protein denaturation and precipitation.
Protein casts with long thin tails formed at the junction of Henle's
loop and the distal convoluted tubule are called cylindroids.
Hyaline casts are seen in
1- Healthy persons
2- Physiological (as in fever, strenuous exercise)
3- Glomerular damage (as in nephrotic syndrome)
MICROSCOPIC URINE EXAMINATION
Casts
Granular casts
Granular casts
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Granular casts can result either from the breakdown of
cellular casts (if persist for long duration in tubules) resulting
in appearance of aggregation of contents of cells without
the cell membranes
Or result from the inclusion of aggregates of plasma proteins
(e.g. albumin) or immunoglobulin light chains to a hyaline
cast
indicative of chronic renal disease
MICROSCOPIC URINE EXAMINATION
Casts
Waxy casts
Waxy casts
• Suggest severe longstanding kidney disease such as
renal failure (end stage renal disease)
• They may appear as an advanced stages of granular
casts
MICROSCOPIC URINE EXAMINATION
Casts
Fatty casts
Formed by the breakdown of lipid-rich epithelial cells, these are
hyaline casts with fat globule inclusions
They can be present in:
• Nephrotic syndrome (due to cholesterol increase in urine)
• Diabetic or lupus nephropathy
• Acute tubular necrosis (damage of tubular cells with release
of fat contents into hyaline casts)
MICROSCOPIC URINE EXAMINATION
Casts
Red Blood Cells Casts
Red Blood Cells Casts
Red blood cells may stick together and form red blood cell casts.
RBCs casts are indicative of:
1- Glomerulonephritis with leakage of RBC's from glomeruli
2- Severe tubular damage
MICROSCOPIC URINE EXAMINATION
Casts
White blood cell casts
White blood cell casts
Indicate inflammation of the kidney as such casts will not
form except in the kidney
1- Acute pyelonephritis (most common cause)
2- Glomerulonephritis.
MICROSCOPIC URINE EXAMINATION
Casts
Epithelial casts
Epithelial casts
This cast is formed by inclusion or adhesion of
desquamated epithelial cells of the tubule lining the casts
These can be seen in
Acute tubular necrosis
MICROSCOPIC URINE EXAMINATION
Crystals
Crystals in alkaline
urine
Crystals in acidic
urine
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Uric acid
Calcium oxalate
Cystine
Leucine
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Ammonium magnesium
phosphates (triple phosphate
crystals)
Calcium carbonate
MICROSCOPIC URINE EXAMINATION
Crystals
Calcium Oxalate
Crystals
Triple Phosphate
Crystals
Uric Acid
Crystals
Cystine
Crystals
crystals
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