1. Dr. SARANYA VINOTH

2.  Lab diagnostics are now becoming a important
and mandatory technique to bring out the
additional information about a patient.
 It makes the clinicians must have an
understanding and working knowledge of
diagnostic modalities other than their own area
of expertise.
 Laboratory diagnostic are usually used in
conjunction with thorough history and physical
examination to know valuable information about
the patient status and response to therapy that
may not be apparent from the history and
physical examination.

3. Generally a diagnostic test is used to
1. Basic screening
2. Establishing diagnosis
3. Differential diagnosis
4. Evaluating current medical
condition
5. Evaluating disease severity
6. Monitoring response of treatment
7. Regularly scheduled screening test
as a part of ongoing care

4.  FACT- Nearly 45 million people surf internet
about medical conditions and diagnostics. It
becomes the responsibility of an physician to
explain them about how it differs from
actual situation.

5. CLINICAL TEAM
PATIENT

6.  Explanation of test
 Indications for testing
 Signs,symptoms and history of disease
 Normal reference values
 Informed consent

7.  Actual description of procedures
 Specimen collection and transport
 Provide comfort to patient
 Interfering factors

8.  Interpret test results
 Provide social support and counsel for
unexpected outcomes
 Order follow up tests at appropriate interval
 Reeducate patient for future testing
 Document and maintain proper records

9.  Ensure the specimens are correctly obtained
,preserved,handled,labeled and delivered to
lab.
 Follow universal precautions and infection
control policies.
 Health care personnel should protect
themselves with appropriate use of
protective measures.

10.  Incorrect specimen collection,handling and
storage
 Wrong or lack of preservative
 Hemolysed blood samples
 Incorrect pretest diet
 Incorrect labeling

11.  Give information that relates to what the
patient will physically feel and the
equipment that will be used
 Encourage questions and verbalization of
feelings,fears and concerns.
 Inform the patient that the test results will
come only after certain period of time.
 Provide emotional support for the patient.

12.  Complete blood count
 Lipid profile
 Fasting blood sugar
 Post prandial blood sugar
 HbA1c
 Urine analysis
 Bilurubin
 SGOT
 SGPT
 ESR
 Blood grouping

13. Pregnancy test
Random blood sugar test
Hemoglobin test
Malaria test
Urine dip test

16.  White blood cell (WBC, leukocyte) count:-
White blood cells protect the body against
infection. If an infection develops, white
blood cells attack and destroy the
bacteria, virus, or other organism causing it.
When a person has a bacterial infection, the
number of white cells rises very quickly. The
number of white blood cells is used to find
an infection .

17.  The major types of white blood cells
are neutrophils, lymphocytes, monocytes, eo
sinophils, and basophils. Immature
neutrophils, called band neutrophils, are also
part of this test. Each type of cell plays a
different role in protecting the body. The
numbers of each one of these types of white
blood cells give important information about
the immune system. Too many or too few of
the different types of white blood cells can
help find an infection, an allergic or toxic
reaction to medicines or chemicals, and
many conditions, such as leukemia.
White blood cell count:-
(WBC differential)

18. Red blood cell (RBC) count.
 Red blood cells carry oxygen from
the lungs to the rest of the body. They also
carry carbon dioxide back to the lungs so it
can be exhaled. If the RBC count is low
(anemia), the body may not be getting the
oxygen it needs. If the count is too high
there is a chance that the red blood cells will
clump together and block tiny blood vessels
(capillaries). This also makes it hard for your
red blood cells to carry oxygen.

19. Hemoglobin (Hgb).
The hemoglobin molecule fills up the
red blood cells. It carries oxygen and
gives the blood cell its red color. The
hemoglobin test measures the amount
of hemoglobin in blood and is a good
measure of the blood's ability to carry
oxygen throughout the body

20. Hematocrit
 This test measures the amount of space
(volume) red blood cells take up in the
blood. The value is given as a percentage of
red blood cells in a volume of blood. For
example, a hematocrit of 38 means that 38%
of the blood's volume is made of red blood
cells. Hematocrit and hemoglobin values are
the two major tests that show if anemia is
present.

21. Red blood cell indices.
There are three red blood cell indices: mean
corpuscular volume (MCV), mean corpuscular
hemoglobin (MCH), and mean corpuscular
hemoglobin concentration (MCHC).The MCV
shows the size of the red blood cells. The MCH
value is the amount of hemoglobin in an average
red blood cell. The MCHC measures the
concentration of hemoglobin in an average red
blood cell. These numbers help in the diagnosis
of different types of anemia.

22. Red cell distribution width
Red cell distribution width (RDW) can
also be measured which shows if the
cells are all the same or different sizes
or shapes.

23. Platelet count (Thrombocyte)
Platelets (Thrombocytes) are the smallest
type of blood cell. They are important in
blood clotting. When bleeding occurs, the
platelets swell, clump together, and form a
sticky plug that helps stop the bleeding. If
there are too few platelets, uncontrolled
bleeding may be a problem. If there are too
many platelets, there is a chance of a blood
clot forming in a blood vessel. Also, platelets
may be involved in hardening of the arteries

24. Keep Taking the Medicine
Patient: It's been one month since my last
visit and I still feel miserable.
Doctor: Did you follow the instructions on
the medicine I gave you?
Patient: I sure did - the bottle said 'keep
tightly closed.

25.  Normal values-4.5-10.5 *10³cells/mm³or 4500-
10500 cells/mm3
 Leucocytosis->11,000mm3
1. Acute severe infections
2. Leukemias
3. Tissue injury
4. Steroid therapy
 Leukopenia <4000mm3
1. Viral infections
2. Drugs like antibiotics,analgesics
3. Aleukemia
4. Aplastic anemia

26. The WBC ‘s are classified majorly into 2
categories
1.Granulocytes(with nucleus)
 Neutrophil
 Basophil
 Eosinophil
2.Agranulocytes(without nucleus)
 Lymphocytes
 Monocytes

27.  It increases in pyogenic(bacterial) infections
 Normal value -3000-7000mm3
 Neutrophilia >8000/mm3
1.Bacterial infection
2.Inflammation
3.chemicals and toxins like venoms
4.carcinomas
 Neutropenia <1800/mm3
1.Viral infections
2.Aplastic anemia

28.  Increases in allergic and parasitic infections
 Normal 0-3%
 Eosinophilia>5% or 500 cells/mm3
1.Allergies
2.Asthma
3.Parasitic disesase
4.Poisons
 Eosiopenia<50/mm3
1.certain drugs like thyroxine

29.  Used to study chronic inflammation
 Normal-0-1% of total WBC
 Basophilia >50/mm3
1. Leukemia,
2. Less commonly in
Inflammation,Allergy,Sinusitis
 Basopenia <20mm3
1. Infection,
2. Hyperthyroid,
3. Stress.

30.  It removes injured and dead cells,micro
organisms and insoluble particles from
circulating blood.
 Normal 3-7% of total WBC
 Monocytosis->500cells/mm3
1. Leukemia,
2. Carcinoma Stomach,Breast.
 Decreased monocyte count <100cells/mm3
1. HIV

31.  Play a main role in immunologic reactions.
 Normal 25-40%
 Lymphocytosis>4000/mm3
1. Leukemia,
2. Viral diseases
3. Tuberculosis
 Lymphopenia <1000/mm3
1. Aplastic anemia
2. HIV

32.  The main function of the red blood cell is to
carry oxygen from lungs to body tissues and to
transfer carbon di oxide from the tissues to
lungs.
Normal
 Men -4.2-5.4*106//mm3
 Women- 3.6-5* 106/mm3
 Decreased RBC’s Occurs in
1. Anemia
2. Increased RBC’S
3. Primary causes like polycythemia vera
4. Secondary cause like renal disease,high
altitude

33.  The test indirectly measures the RBC mass.
Normal-
 Men 42-52%
 Women 36-48%
 Decreased HCT<30 % in Anemia,Leukemia
 Increased HCT in shock.

34.  Hb is the main component of erythrocytes
serves as vehicle for transportation of oxygen
and carbon di oxide.
 Women 12-16gms/dl
 Men 14-17 gms/dl
 Decreased hemoglobin in Iron
deficiency,Liver disease,Pregnancy.
 Increased hemoglobin in COPD,Congestive
heart disease.

35.  The red blood cell indices define the size and
Hb content of RBC and consist
 Mean corpuscular volume(MCV),
 Mean corpuscular hemoglobin
concentration(MCHC)and
 Mean corpuscular hemoglobin(MCH).

36.  This index expresses the volume occupied by
single erythrocyte and measured in cubic
micro meter or femtolitre.The MCV indicates
whether the red blood cell size appears
normal or smaller.
 Normal 82-98mm3or 82-98fL
 Used to find the type of anemia.

37.  This gives the information about the average
concentration of Hb in RBC’s.
 Used in monitoring the anemia therapy.
 Normal 32-36 g/Dl

38.  The MCH is a measure of average weight of
Hb per RBC.
 It is used in knowing the severe anemic
patients.

39.  This indicates the size variation of RBC.This
measurement is useful in monitoring
response to therapy.
 Normal value-11.5-14.5
 Increased in iron deficiency,perncious
anemia.

40.  Platelet activity is necessary for blood
clotting,vasoconstriction and adhesion and
aggregation activity.
 Normal
 Adult 140-400*103/mm3
 Children 150-450*103/mm3
 Abnormally increased in renal failure,iron
deficiency anemia,malignancy.
 Abnormally decreased in anemia,congestive
heart failure,HIV.
 A decrease in <20*103/mm3 platelets is
associated with spontaneous bleeding,petechiae

41.  The MPV indicates the uniformity of size of
platelet population.
 Adult and children-7.4-10.4 fL.
 MPV increased in massive hemorrhage,

42.  P-LCR tells about the ratio of large platelets.
 Normal values-14-44%
 Increased in vascular
disease,hyperlidipiemia.

43.  An indication of variation in platelet size
which can be a sign of active platelet
release.
 PWD Normal Values:
 9 - 13 fL
 Clinical implications:
 Increased PWD:
 Iron Deficiency Anemia
 Folate and vitamin B12 deficiency anemia
 Hemorrhage.

44.  Eryhthrocyte sedimentation occurs at higher
level when inflammatory or necrotic process is
present.
 ESR is used to find the monitor in progression of
disease or treatment outcome.
 Normal value
 Men-0-15mm/hr
 Women—20mm/hr
 Slightly increased in people over 50 yrs of age.
 Increased ESR is seen in Infections,Inflammatory
processes.
 Normal or same in iron deficiency anemia .

45. Blood group A
If you belong to the blood group
A, you have A antigens on the
surface of your red blood cells and B
antibodies in your blood plasma.
Blood group B
If you belong to the blood group
B, you have B antigens on the
surface of your red blood cells and A
antibodies in your blood plasma.
Blood group AB
If you belong to the blood group
AB, you have both A and B antigens
on the surface of your red blood
cells and no A or B antibodies at all
in your blood plasma.
Blood group 0
If you belong to the blood group 0
(null), you have neither A or B
antigens on the surface of your red
blood cells but you have both A and
B antibodies in your blood plasma.

46.  Doctor, Doctor When I press with my finger
here... it hurts, and here... it hurts, and
here... and here... What do you think is
wrong with me?
 You have a broken finger!

48.  Lipid measures are diagnostic indicators of
hyper or hypolipidemia.
 The components are
 Total cholesterol
 Triglycerides
 High density lipids
 Low density lipids

49.  Cholesterol is a lipid (fat) which is produced by
the liver. Cholesterol is vital for normal body
function. Every cell in our body has cholesterol
in its outer layer.
 What are the functions of cholesterol?
 It builds and maintains cell membranes (outer
layer),
 It is essential for determining which molecules
can pass into the cell and which cannot (cell
membrane permeability)
 It is involved in the production of hormones
(androgens ,estrogens,cortisol etc)
 It is important for the metabolism of fat
soluble vitamins, including vitamins A, D, E, and
K
 It insulates nerve fibers

50. TOTAL CHOLESTEROL
 Normal values;
 Adult
 Desirable - Less than 200 mg/dL
 Bordeline high - 200 to 239 mg/dL
 High - 240 mg/dL and above
 Children
 Desirable - Less than 170 mg/dL
 Bordeline high – 170-200 mg/dL
 High – 200 mg/dL and above
 Hyperlidemia occurs in renal
failure,hypothyroidism,alchoholism,obesity
 Hypolidemia occurs in hyperthyroidism,severe
burns,mental retardation.

51.  There are three main types of lipoproteins
 Cholesterol is carried in the blood by
molecules called lipoproteins. A lipoprotein is
any complex or compound containing both
lipid (fat) and protein. The three main types
are:
 Low Density Lipid
 High Density Lipid
 Triglycerides

52.  LDL (low density lipoprotein) - people often
refer to it as bad cholesterol. LDL carries
cholesterol from the liver to cells. If too much is
carried, too much for the cells to use, there can
be a harmful buildup of LDL. This lipoprotein can
increase the risk of arterial disease if levels rise
too high. Most human blood contains
approximately 70% LDL.
 Normal values
 Adults-
 Desirable-<130mg/dl
 Borderline high-140-159mg/dl
 High-160mg/dl
 Increased in familial
hypercholesterolemia,obesity,dibetes mellitus
 Decreased in hyperthyroidism,chronic anemias.

53.  HDL (high density lipoprotein) - people often
refer to it as good cholesterol. Experts say HDL
prevents arterial disease. HDL does the opposite
of LDL - HDL takes the cholesterol away from the
cells and back to the liver. In the liver it is either
broken down or expelled from the body as
waste.
 Normal values
 Men 35-65mg/dl
 Women 35-80mg/dl
 Increased in long term aerobics or vigorous
exercise
 Decreased in poorly controlled diabetes
mellitus,chronis renal disease.

54.  Triglycerides - these are the chemical forms in
which most fat exists in the body, as well as in
food. They are present in blood plasma.
Triglycerides, in association with
cholesterol, form the plasma lipids (blood fat).
Triglycerides in plasma originate either from fats
in our food, or are made in the body from other
energy sources, such as carbohydrates. Calories
we consume but are not used immediately by our
tissues are converted into triglycerides and
stored in fat cells. When your body needs energy
and there is no food as an energy
source, triglycerides will be released from fat
cells and used as energy - hormones control this
process.

55.  Desirable-<150mg/dl
 Borderline high-150-199mg/dl
 High 200-499mg/dl
 Increased in hypothyroidism,renal
disease,poorly controlled diabetes.
 Decreased in
malnutrition,hyperthyroidism

58.  SGOT or Aspartate transaminase(AST) is
widely distributed in tissues with highest
concentration found in liver,heart,skeletal
muscles and kidney. Diseases involving much
of these tissues results in increase in AST in
serum.
 Normal range
 Men-14-20 U/L
 Women 10-36 U/L
 Increased AST in hepatitis,acute
cirrhosis,alcoholic hepatitis.
 Decreased AST in vitamin B6 deficiency.

59.  SGPT or Alanine aminotransferase(ALT) is
found in many tissues especially high in liver
which ultimately results rise of ALT in liver
disease.
 Normal value
 Men-10-40U/L
 Women 7-35U/L
 Increased ALT in viral disease,burns,alcoholic
cirrhosis.

60.  Bilirubin is a brownish yellow substance found in bile.
It is produced when the liver breaks down old red
blood cells. Bilirubin is then removed from the body
through the stool (feces) and gives stool its normal
brown color.
 Indirect (or unconjugated) bilirubin. This form of
bilirubin does not dissolve in water (it is insoluble).
Indirect bilirubin travels through the bloodstream to
the liver, where it is changed into a soluble form
(direct or conjugated).
 Direct (or conjugated) bilirubin. Direct bilirubin
dissolves in water (it is soluble) and is made by the
liver from indirect bilirubin.
 Normal values
 Total 0.3-1.0 mg/dL
 Conjugated 0-0.2mg/dl
 Used to check liver function and watch for signs of
liver disease such as hepatitis or cirrhosis, or the
effects of medicines that can damage the liver.

63.  Fasting blood sugar is taken when the blood
glucose level is tested after 8 hrs of nil
caloric intake.
 Normal FBS -<65-110mg/dL
 Increased in diabetes mellitus,acute
emotional or stress,chronic liver disease.
 Decreased in starvation,liver
damage,hypothyroidism

64.  A postprandial glucose test is a blood
glucose test that determines the amount of a
type of sugar, called glucose, in the blood
after a meal. Glucose comes
from carbohydrate foods. It is the main
source of energy used by the body.
 Normal value-<140 mg/dl
 Increased in diabetes
mellitus,pregnancy,advanced liver disease
 Decreased in carcinoma,liver damage.

65.  The A1C test is a common blood test used to diagnose
type 1 and type 2 diabetes and then to gauge how
well you're managing your diabetes. The A1C test
goes by many other names, including glycated
hemoglobin, glycosylated hemoglobin, hemoglobin
A1C and HbA1c.
 The A1C test result reflects your average blood sugar
level for the past two to three months.
Specifically, the A1C test measures what percentage
of your hemoglobin — a protein in red blood cells that
carries oxygen — is coated with sugar (glycated). The
higher your A1C level, the poorer your blood sugar
control and the higher your risk of diabetes
complications.
 Normal
 4%-6% -Normal
 6-7% -Target range for diabetics
 >7% -High

66.  The tongue is the strongest muscle in the
human body.
 Enamel is hardest substance in the human
body
 The only part of the body that has no blood
supply is the cornea in the eye. It takes in
oxygen directly from the air.
 The Hyoid bone, in your throat ,is the only
bone in your body which not attached to
other bone..
 There are 60,000 miles (97,000 km) of blood
vessels in each human.

68.  Specific gravity is a measurement of kidney
ability to concentrate urine and is a measure
of density of dissolved chemicals in urine .
 Normal 1.005-1.030
 Increased in dehydration,diabetes mellitus,
 Decreased in severe renal
damage,Glomerulonephritis

69.  The pH is an indicator of renal tubules ability
to maintain normal hydrogen ion
concentration in plasma and extracellular
fluid. The importance of urinary ph used in
determining existence of acid base disorders
 Normal 6.0-8
 Acidic urine<7 in UTI,metabolic
acidosis,diarrhea.
 Alkaline urine >7 in chronic renal
failure,vomiting.

70.  Presence of free hemoglobin in urine is
referred as hemoglobinuria. Blood in urine is
always a result of trauma or damage to
kidney or urinary tract.
 Normal <10 erythroytes/µL,0.003mg free
Hb/dL
 Hematuria is found in UTI,trauma to
kidney,urinary calculi.
 Hemoglobinuria is found in
burns,malaria,disseminated intravascular
coagulation.

71.  The presence of increased amount of protein
in urine can be an important indicator of
renal disease.It may be the first sign of a
serious problem and may appear before any
other clinical symptoms.
 Normal
 Negative
 Adult male 1-14mg/dl
 Adult female 3-10mg/dl

72.  Glucose is present in glomerular filtrate and
is reabsorbed by proximal convoluted
tubule.if the blood glucose level exceeds
reabsorption capacity of tubules glucose will
appear in urine.
 Normal
 Random specimen –Negative
 24 hour specimen 1-15mg/dl
 Increased glucose appears in diabetes
mellitus,endocrine disorders.

73.  In normal healthy persons ketones are
formed in liver and are completely
metabolized so that only negligible amounts
appear in urine.increased ketones in the
blood lead to electrolyte imbalance ,acidosis
and eventually coma.The excess presence of
ketones in urine is associated with diabetes.
 Normal
 Urine-negative(0.03-0.05 mmol/L)
 Ketosis is found in diabetes mellitus,dietary
conditions like starvation.

74.  Urine nitrite
 This test is an indirect method to detect
bacteria in urine.
 Normal –negative
 Urine leukocyte
 The presence of leukocytes in urine indicates
a UTI.
 Normal –negative

75.  Bilurubin is formed as a breakdown product
of hemoglobin .It aids in diagnosis of
monitoring and treatment of hepatitis and
liver disease.
 Normal –negative (0-0.02mg/dl)

76.  Urobilinogen is also a breakdown product of
hemoglobin .it is one of the most sensitive
test to determine impaired liver function.
 Normal –negative<1mg/dl
 Increased in malaria,hemolytic anemia.

77. p
Leukocytes
Nitrite
Urobilinogen
Protein
pH
Haemoglobin
Specific gravity
Ketone
Bilirubin
Glucose

78.  A blood urea nitrogen (BUN) test measures the
amount of nitrogen in blood that comes from
the waste product urea. Urea is made when
protein is broken down in your body. Urea is
made in the liver and passed out of body in the
urine.
 A BUN test is done to see how well kidneys are
working. If kidneys are not able to remove urea
from the blood normally, BUN level rises.
 Normal
 Adult 6-20mg/dl
 Elderly 8-23mg/dl
 Increased BUN in chronic renal disease,urinary
tract obstruction,diabetes mellitus
 Decreased BUN in liver
failure,malnutrition,nephrotic syndrome.

79.  Creatinine is a breakdown product of creatine, which
is an important part of muscle. Creatinine is removed
from the body entirely by the kidneys. If kidney
function is abnormal, creatinine levels will increase
in the blood .

 Normal
 Men 0.7 to 1.3 mg/dL
 Women 0.6 to 1.1 mg/dL
 Higher than normal levels may be due to:
 Acute tubular necrosis
 Dehydration
 Diabetic nephropathy
 Lower than normal levels may be due to:
 Muscular dystrophy
 Myasthenia gravis

80.  Uric acid is a chemical created when the
body breaks down substances called purines.
Purines are found in some foods and
drinks, such as liver.Most uric acid dissolves
in blood and travels to the kidneys, where it
passes out in urine. High levels of uric acid in
the body is called hyperuricemia.
 Normal
 Men 3.4-7.0 mg/dl
 Women 2.4-6.0 mg/dl
 Elevated uric acid levels in renal disease and
renal failure,alcoholism,liver disease
 Decreased uric acid levels in malignancies.

81.  Magnesium in the body is concentrated in
bone(40-60%)and also in muscle and serum.it
is used to evaluate renal function,electrolyte
status.
 Normal
 Adult-1.8-2.6 mg/dl
 Children 1.7-2.1 mg/dl
 Hypomagnesemia occurs in
hypercalcemia,diabetic acidosis,chronic
renal disease.
 Hypermagnesemia occurs in renal
failure,dehydration,hypothyroidism.

82.  Albumin is a protein manufactured by the liver.
It helps balance the amount of blood flowing
through the arteries and veins and moves the
calcium, progesterone, bilirubin and medications
through a person’s blood. It also stops fluid in
the blood from leaking into the tissues.
 Albumin is used to evaluate nutritional
status,liver disease,renal disease.
 Normal
 Adult-3.5-5.2 g/dl
 Increased in dehydration
 Decreased in cirrhosis,liver
disease,burns,alcoholism

83.  The WIDAL is the diagnostic test for
salmonella typhi infection causing typhoid.
 The titre of 1:80 is considered as positive in
typhoid endemic countries like India.
 Widal is not so reliable to typhoid as its titre
will also be raised in viral infections.
 The results should be correlated with clinical
syptoms.