It ’ s not just water ! An introduction to Urinalysis as performed in the Clinical Laboratory.

ItIt’’s not just water !s not just water !

An introduction to Urinalysis An introduction to Urinalysis

as performed in the as performed in the

Clinical Laboratory.Clinical Laboratory.

What is Urinalysis?What is Urinalysis?

Urinalysis – or the Urinalysis – or the analysis of urine analysis of urine – is one of the – is one of the oldest laboratory oldest laboratory procedures in the procedures in the practice of practice of medicine.medicine.

It is a good test It is a good test for assessing the for assessing the overall health of overall health of a patient. a patient.

Courtesy of the National Library of Medicine

What is Urinalysis?What is Urinalysis?

It provides information about:It provides information about:– The state of the kidney and urinary tract.The state of the kidney and urinary tract.– Metabolic or systemic (non-kidney) Metabolic or systemic (non-kidney)

disorders.disorders.

Urinalysis can reveal diseases that have Urinalysis can reveal diseases that have gone unnoticed because they do not gone unnoticed because they do not produce striking signs or symptoms. produce striking signs or symptoms. – Examples include diabetes mellitus, Examples include diabetes mellitus,

various forms of kidney failure, and various forms of kidney failure, and chronic urinary tract infections.chronic urinary tract infections.

UrinalysisUrinalysis

Renal function tests, such as the Renal function tests, such as the urinalysis, are used to screen for the urinalysis, are used to screen for the cause and the extent of renal cause and the extent of renal dysfunction.dysfunction.

Urinalysis consists of the following Urinalysis consists of the following measurements:measurements:– Macroscopic examMacroscopic exam– Chemical exam Chemical exam – Microscopic exam of the sedimentMicroscopic exam of the sediment

Macroscopic ExamMacroscopic Exam

Examination of Examination of the physical the physical properties properties including….including….– ColorColor– Clarity (or Clarity (or

transparency)transparency)


Color - normalColor - normal– yellow (straw to amber)yellow (straw to amber)

Color - abnormal (due to disease, drugs Color - abnormal (due to disease, drugs or diet)or diet)– pale to colorless pale to colorless – amber (dark yellow)amber (dark yellow)– orange orange – pink or redpink or red– greengreen– brown or blackbrown or black


Clarity (or transparency) - normalClarity (or transparency) - normal– clear

Clarity - abnormal (due to Clarity - abnormal (due to insoluble elements such as cells, insoluble elements such as cells, crystals, etc.)crystals, etc.)– hazyhazy– cloudycloudy– turbidturbid


Left to right: Straw, clear; yellow, clear; yellow, hazy; yellow, clear; red-orange, clear; brown, hazy.

Chemical ExamChemical Exam

The presence of The presence of normal and abnormal normal and abnormal chemical elements in chemical elements in the urine are detected the urine are detected using dry reagent using dry reagent strips.strips.

These plastic strips These plastic strips contain absorbent contain absorbent pads with various pads with various chemical reagents for chemical reagents for determining a specific determining a specific substance.substance.


When the test When the test strip is dipped strip is dipped in urine the in urine the reagents are reagents are activated and a activated and a chemical chemical reaction occurs. reaction occurs.

The chemical The chemical reaction results reaction results in a specific in a specific color change. color change.


After a specific After a specific amount of time amount of time has elapse, this has elapse, this color change is color change is compared compared against a against a reference color reference color chart provided chart provided by the by the manufacturer manufacturer of the strips. of the strips.

Chemical Reaction Chemical Reaction ChartChart


The intensity of the color formed The intensity of the color formed is generally proportional to the is generally proportional to the amount of substance present. amount of substance present.

Typical Substances Typical Substances Tested & SignificanceTested & Significance pHpH - partial assessment of acid base status; - partial assessment of acid base status;

alkaline pH indicates old sample or urinary tract alkaline pH indicates old sample or urinary tract infectioninfection

Specific GravitySpecific Gravity - - state of kidney and state of kidney and hydration status of patient hydration status of patient

ProteinProtein - - primarily detects protein called primarily detects protein called albumin; important indicator in the detection of albumin; important indicator in the detection of renal diseaserenal disease

GlucoseGlucose - - primarily detects glucose (sugar); primarily detects glucose (sugar); important indicator of diabetes mellitusimportant indicator of diabetes mellitus

Typical Substances Typical Substances Tested & SignificanceTested & Significance Blood Blood - red blood cells, hemoglobin, or - red blood cells, hemoglobin, or

myoglobin (muscle hemoglobin); sensitive early myoglobin (muscle hemoglobin); sensitive early indicator of renal diseaseindicator of renal disease

KetoneKetone - normal product of fat metabolism; - normal product of fat metabolism; increased amounts seen in diabetes or starvation increased amounts seen in diabetes or starvation (extreme dieting)(extreme dieting)

BilirubinBilirubin - detects bilirubin (a product of red cell - detects bilirubin (a product of red cell breakdown); indicator of liver function breakdown); indicator of liver function

UrobilinogenUrobilinogen - another by-product of red cell - another by-product of red cell breakdown; increased amounts seen in fever, breakdown; increased amounts seen in fever, dehydration, hemolytic anemia and liver diseasedehydration, hemolytic anemia and liver disease

Typical Substances Typical Substances Tested & SignificanceTested & Significance

NitriteNitrite - certain bacteria convert normal - certain bacteria convert normal urine nitrate to nitrite; indicator of urinary urine nitrate to nitrite; indicator of urinary tract infection tract infection

Leukocyte EsteraseLeukocyte Esterase - - detects esterase detects esterase enzyme present in certain white blood cells enzyme present in certain white blood cells (e.g, neutrophils, monocytes); indicator of (e.g, neutrophils, monocytes); indicator of urinary tract infectionurinary tract infection

Example Chemical Example Chemical Analysis Results ...Analysis Results ...

Elevated pH (alkaline)Elevated pH (alkaline)

(Normal for comparison) (Normal for comparison)

Positive GlucosePositive Glucose


Positive Blood & Positive Blood & KetonesKetones


Positive Blood and Positive Blood and Leukocyte EsteraseLeukocyte Esterase


If you see…If you see… Red blood cells- bladder infection, Red blood cells- bladder infection,

kidney stones, kidney disease, tumor, kidney stones, kidney disease, tumor, cancer, traumatic injurycancer, traumatic injury

White blood cells- UTI or kidney White blood cells- UTI or kidney infectioninfection

Protein- kidney diseaseProtein- kidney disease Glucose- diabetes Glucose- diabetes Nitrates- UTINitrates- UTI Ketones- diabetes and kidney failureKetones- diabetes and kidney failure

Microscopic ExamMicroscopic Exam

Most commonly used procedure Most commonly used procedure for the detection of renal and/or for the detection of renal and/or urinary tract disease.urinary tract disease.

This exam consists of reviewing This exam consists of reviewing the solid material suspended in the solid material suspended in the urine - both chemical and the urine - both chemical and cellular. cellular.


The urine The urine specimen is specimen is centrifuged centrifuged and the and the liquid portion liquid portion is poured off.is poured off.

The The concentrateconcentrated cellular d cellular sediment …. sediment ….


……. is then . is then placed on a placed on a microscope microscope slide, slide, covered covered with a with a coverslip coverslip and ….and ….


… … viewed under a microscope.viewed under a microscope.


A variety of normal and abnormal A variety of normal and abnormal cellular elements may be seen in cellular elements may be seen in urine sediment such as:urine sediment such as:– Red blood cellsRed blood cells– White blood cellsWhite blood cells– MucusMucus– Various epithelial cellsVarious epithelial cells– Various crystalsVarious crystals– BacteriaBacteria


Red blood cellsRed blood cells– presence of a presence of a

few is normalfew is normal– higher numbers higher numbers

are indicator of are indicator of renal diseaserenal disease

– result of bleeding result of bleeding at any point in at any point in urinary systemurinary system

40x objective


White blood cellsWhite blood cells– a few are normala few are normal– high numbers high numbers

indicate indicate inflammation or inflammation or infection infection somewhere along somewhere along the urinary or the urinary or genital tractgenital tract

40x objective


MucusMucus– look like long, look like long,

ribbon-like ribbon-like threadsthreads

– common finding common finding in urine sedimentin urine sediment

– secreted by secreted by glands in the glands in the lower urinary lower urinary tracttract

40x objective


Epithelial cellsEpithelial cells– cells are large cells are large

and flatand flat– normal cells normal cells

that line the that line the urinary and urinary and genital tract or genital tract or renal tubulesrenal tubules

40x objective


A variety of A variety of normal and normal and abnormal abnormal crystals may crystals may be present in be present in the urine the urine sediment.sediment.


Crystals of calcium Crystals of calcium oxalateoxalate– colorless octahedroncolorless octahedron– found in acid urinefound in acid urine

Crystals of triple Crystals of triple phosphatephosphate– colorless, colorless, ““coffin-lidcoffin-lid””

prism prism – common finding; not common finding; not

clinically significantclinically significant


Hyaline CastsHyaline Casts– colorless and colorless and

fatter than mucusfatter than mucus– a few are normala few are normal– may be increased may be increased

after strenuous after strenuous exerciseexercise

– form when form when protein solidifies protein solidifies in the nephronin the nephron

Hyaline cast & epithelial cell, 40x objective

An additional note ...An additional note ...

The chemical and microscopic analysis The chemical and microscopic analysis of urine can be performed manually or of urine can be performed manually or with automated analyzers.with automated analyzers.

In many laboratories, abnormal In many laboratories, abnormal automated findings are confirmed by automated findings are confirmed by manual techniques.manual techniques.

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It ’ s not just water ! An introduction to Urinalysis as performed in the Clinical Laboratory.

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