COMPLETE BLOOD COUNT (CBC)

Overview

The complete blood count (CBC) is one of the most commonly ordered blood tests. The
complete blood count is the calculation of the cellular (formed elements) of blood. These
calculations are generally determined by special machines that analyze the different
components of blood in less than a minute.

A major portion of the complete blood count is the measure of the concentration of white
blood cells, red blood cells, and platelets in the blood.

Normal Values

The values generally included are the following:

 White blood cell count (WBC) is the number of white blood cells in a volume of
blood. Normal range varies slightly between laboratories but is generally between
4,300 and 10,800 cells per cubic millimeter (cmm). This can also be referred to
as the leukocyte count and can be expressed in international units as 4.3 to 10.8
x 109 cells per liter.

 White blood cell (WBC) differential count. White blood count is comprised of
several different types that are differentiated, or distinguished, based on their
size and shape. The cells in a differential count are granulocytes, lymphocytes,
monocytes, eosinophils, and basophils.

A machine generated percentage of the different types of white blood cells is called the
automated WBC differential. These components can also be counted under the
microscope on a glass slide by a trained laboratory technician or a doctor and referred
to as the manual WBC differential.

 Red cell count (RBC) signifies the number of red blood cells in a volume of
blood. Normal range varies slightly between laboratories but is generally between
4.2 to 5.9 million cells/cmm. This can also be referred to as the erythrocyte count
and can be expressed in international units as 4.2 to 5.9 x 1012 cells per liter.

Red blood cells are the most common cell type in blood and people have millions of
them in their blood circulation. They are smaller than white blood cells, but larger than
platelets.

 Hemoglobin (Hb). This is the amount of hemoglobin in a volume of blood.

Hemoglobin is the protein molecule within red blood cells that carries oxygen and
gives blood its red color. Normal range for hemoglobin is different between the
 sexes and is approximately 13 to 18 grams per deciliter for men and 12 to 16 for
women (international units 8.1 to 11.2 millimoles/liter for men, 7.4 to 9.9 for
women).

 Hematocrit (Hct). This is the ratio of the volume of red cells to the volume of
whole blood. Normal range for hematocrit is different between the sexes and is
approximately 45% to 52% for men and 37% to 48% for women. This is usually
measured by spinning down a sample of blood in a test tube, which causes the
red blood cells to pack at the bottom of the tube.

 Mean corpuscular volume (MCV) is the average volume of a red blood cell.
This is a calculated value derived from the hematocrit and red cell count. Normal
range may fall between 80 to 100 femtoliters (a fraction of one millionth of a liter).

 Mean Corpuscular Hemoglobin (MCH) is the average amount of hemoglobin in

the average red cell. This is a calculated value derived from the measurement of
hemoglobin and the red cell count. Normal range is 27 to 32 picograms.

 Mean Corpuscular Hemoglobin Concentration (MCHC) is the average

concentration of hemoglobin in a given volume of red cells. This is a calculated
volume derived from the hemoglobin measurement and the hematocrit. Normal
range is 32% to 36%.

 Red Cell Distribution Width (RDW) is a measurement of the variability of red

cell size and shape. Higher numbers indicate greater variation in size. Normal
range is 11 to 15.

 Platelet count. The number of platelets in a specified volume of blood. Platelets

are not complete cells, but actually fragments of cytoplasm (part of a cell without
its nucleus or the body of a cell) from a cell found in the bone marrow called a
megakaryocyte. Platelets play a vital role in blood clotting. Normal range varies
slightly between laboratories but is in the range of 150,000 to 400,000/ cmm (150
to 400 x 109/liter).

 Mean Platelet Volume (MPV). The average size of platelets in a volume of

blood.

What is the complete blood count (CBC) used for?

Your doctor may order this test for a variety of reasons. It may be a part of a routine
check-up or screening, or as a follow-up test to monitor certain treatments. It can also
be done as a part of an evaluation based on a patient's symptoms.

For example, a high WBC count (leukocytosis) may signify an infection somewhere in
the body or, less commonly, it may signify an underlying malignancy. A low WBC count
(leukopenia) may point toward a bone marrow problem or related to some medications,
such as chemotherapy. A doctor may order the test to follow the WBC count in order to
monitor the response to a treatment for an infection. The components in the differential
of the WBC count also have specific functions and if altered, they may provide clues for
particular conditions.

A low red blood cell count or low hemoglobin may suggest anemia, which can have
many causes. Possible causes of high red blood cell count or hemoglobin
(erythrocytosis) may include bone marrow disease or low blood oxygen levels (hypoxia).

A low platelet count (thrombocytopenia) may be the cause of prolonged bleeding or

other medical conditions. Conversely, a high platelet count (thrombocytosis) may point
toward a bone marrow problem or severe inflammation.

A complete blood count (CBC) is a calculation of the cellular makeup of blood. A CBC
measures the concentration of white blood cells, red blood cells, and platelets in the
blood and aids in diagnosing conditions and disease such as malignancy, anemia, or
blood clotting problems.

Platelet Count (PC)

Overview

• Test function of platelets, or thrombocytes, which promote coagulation and formation

of a hemostatic plu in vascular injury

• Deterimine ability of patient’s blood to clot normally

Purpose

• To evaluate platelet production

• To assess the effects of chemotheraphy or radiation theraphy on platelet production

• To diagnose and monitor severe thrombocytosis or thrombocytopenia

• To confirm a visual estimate of platelet number and morphology from a stained blood
film

Interpretation

Normal results

• Adults, 140,000 to 400,000/µl (SI,140 to 400 x 10 9 /L)

• Children, 150,000 to 450,000/µl (SI, 150 TO 450 X 10 9 /L)

Abnormal results

• A count below 50,000/µl can cause spontaneous bleeding; when the count is below
5,000/µl, fatal central nervous system bleeding or massive GI hemorrhage is possible.

• A decreased count (thrombocytopenia, 80 to 100 million platelets per ml ) can result

from aplastic or hypoplastic bone marrow; infiltrative bone marrow disease, such as
leukemia, or disseminated infection; megakaryocytic hypolasia; ineffective
thrombopoiesis caused by folic acid or vitamin B12 deficiency; pooling of platelets in an
enlarged spleen; increased platelet destructione; caused by drugs or immune disorders;
disseminated intravascular coagulation; Bernard-Soulier syndrome; or mechanical injury
to platelets.

• An increased count (thrombocytosis) can result from hemorrhage, infectious disorders,

iron deficiency anemia, recent surgery, pregnancy, splenectomy, or inflammatory
disorders. In such cases, the platelet count returns to normal after the patients recovers
from the primary disorder.

• An increased count remains elevated in primary thrombocytopenia, myelofibrosis with

myeloid metaplasia, polycythemia vera, and chronic myelogenous leukemia.

• Whenever the platelet count is abnormal, diagnosis usually requires a complete blood
count, bone marrow biopsy, direct antiglobulin test (direct Coombs’ test), and serum
protein electrophoresis for confirmation.

Prothrombin time (PT)

Overview

Measures the amount of time it takes in seconds for clot formation and is used to
monitor response to warfarin sodium (Coumadin) therapy or to screen for dysfunction of
the extrinsic clotting system resulting from liver disease, vitamin K deficiency, or
disseminated intravascular coagulation.

Purpose
• To evaluate the extrinsic coagulation system (factors V, VII, and X and prothrombin
and fibrinogen)
• To monitor response to oral anticoagulant therapy
Interpretation

Normal Results
• PT should be 10 to 14 seconds depending on the source of tissue thromboplastin and
the type of sensing devices used to measure the clot formation.
• In patient receiving oral anticoagulants, the PT should be from 1 to 2 1/2 times the
normal control value.
Abnormal Results
• Prolonged PT may indicate deficiencies in fibrinogens, prothrombin, factors V, VIII, or
X or vitamin K. It may also result from ongoing oral anticoagulant therapy.

Partial Thromboplastin Time (PTT)

Overview

Used to evaluate all the clotting factors of the intrinsic pathway -- except platelets -- by
measuring the time required for formation of a fibrin clot after the addition of calcium
and phospholipid emulsion to a plasma sample

Purpose

• To screen deficiencies of the clotting factors in the intrinsic pathway

• To monitor response to heparin therapy

Interpretation

Normal Results
• A fibrin clot forms 21 to 35 seconds after adding reagents.
• For a patient receiving an anticoagulants, ask the physicians to specify the reference
values for the therapy being delivered.
Abnormal Results
• A prolonged PTT may indicate a deficiency of certain plasma factors, the presence of
heparin, or the presence of fibrin split products, fibrinolysins, or circulating
anticoagulants that are antibodies to specific clotting factors.

CHEST X-RAY

Overview

A chest X-ray is a radiology test that involves exposing the chest briefly to radiation to
produce an image of the chest and the internal organs of the chest. An X-ray film is
positioned against the body opposite the camera, which sends out a very small dose of
a radiation beam. As the radiation penetrates the body, it is absorbed in varying
amounts by different body tissues depending on the tissue's composition of air, water,
blood, bone, or muscle. Bones, for example, absorb much of the X-ray radiation while
lung tissue (which is filled with mostly air) absorbs very little, allowing most of the X-ray
beam to pass through the lung.

Normal Results

Normal chest X-ray shows normal size and shape of the chest wall and the main
structures in the chest.

As described earlier, white shadows on the chest X-ray signify solid structures and
fluids such as, bone of the rib cage, vertebrae, heart, aorta, and bones of the shoulders.
The dark background on the chest X-rays represents air filled lungs. These lung fields
are seen on either side of the heart and the vertebrae located in the center of the film.

Abnormal Results

Chest X-ray is generally used in combination with other clinical data such as, physical
examination and the patient's history and symptoms. It can also be used in combination
of other radiology test to support, confirm, or exclude many conditions or diagnoses.

A chest X-ray can be used to define abnormalities of the lungs such as excessive fluid
(fluid overload or pulmonary edema) fluid around the lung (pleurisy), pneumonia,
bronchitis, asthma, cysts, and cancers. Heart abnormalities, including fluid around the
heart (pericarditis), an enlarged heart (cardiomegaly), heart failure, or abnormal
anatomy of the heart can be revealed on the films. Certain bony structures of the chest
and broken bones (rib fracture) or abnormalities of the bones of the spine (vertebral
fracture) in the chest can often be detected.
 Blood Typing

Overview

Blood typing is a method to tell what specific type of blood you have. What type you
have depends on whether or not there are certain proteins, called antigens, on your red
blood cells.

Blood is often grouped according to the ABO blood typing system. This method breaks
blood types down into four categories:

 Type A
 Type B
 Type AB
 Type O

Your blood type (or blood group) depends on the types that are been passed down to
you from your parents.

Purpose

This test is done to determine a person's blood type. Health care providers need to
know your blood type when you get a blood transfusion or transplant, because not all
blood types are compatible with each other. For example:

 If you have type A blood, you can only receive types A and O blood.
 If you have type B blood, you can you can only receive types B and O blood.
 If you have type AB blood, you can receive types A, B, AB, and O blood.
 If you have type O blood, you can you can only receive type O blood.

Type O blood can be given to anyone with any blood type. That is why people with type
O blood are called universal blood donors.

Blood typing is especially important during pregnancy. If the mother is found to be Rh-,
the father should also be tested. If the father has Rh+ blood, the mother needs to
receive a treatment to help prevent the development of substances that may harm the
unborn baby. See: Rh incompatibilityRh incompatibility

If you are Rh+, you can receive Rh+ or Rh- blood. If you are Rh-, you can only receive
Rh- blood.
Interpretation

Normal Results

ABO typing:

If your blood cells stick together when mixed with:

 Anti-A serum, you have type A blood

 Anti-B serum, you have type B blood
 Both anti-A and anti-B serums, you have type AB blood

If your blood cells do not stick together when anti-A and anti-B are added, you have
type O blood.

Back typing:

 If the blood clumps together only when B cells are added to your sample, you
have type A blood.
 If the blood clumps together only when A cells are added to your sample, you
have type B blood.
 If the blood clumps together when either types of cells are added to your sample,
you have type O blood.

Lack of blood cells sticking together when your sample is mixed with both types of blood
indicates you have type AB blood.

RH typing:

 If your blood cells stick together when mixed with anti-Rh serum, you have type
Rh-positive blood.
 If your blood does not clot when mixed with anti-Rh serum, you have type Rh-
negative blood.

URINALYSIS

Overview

A urinalysis is simply an analysis of the urine. It is a very common test that can be
performed in many healthcare settings including doctors' offices, urgent care facilities,
laboratories, and hospitals.
it is performed by collecting a urine sample from the patient in a specimen cup. Usually
only small amounts (30-60 ml's) may be required for urinalysis testing. The sample can
be either analyzed in the medical clinic or sent to a laboratory to perform the tests.
Urinalysis is abbreviated UA.

Urine can be evaluated by its physical appearance (color, cloudiness, odor, clarity), or
macroscopic analysis. It can be also analyzed based on its chemical and molecular
properties or microscopic assessment.

Urinalysis is ordered by doctors for a number of reasons, as follows:

 Routine medical evaluation: general yearly screening, assessment before

surgery (pre-operative assessment), admission to hospital, screening for kidney
disease, diabetes mellitus, hypertension (high blood pressure), liver disease, etc.

 Assessing particular symptoms: abdominal pain, painful urination, flank pain,

fever, blood in the urine, or other urinary symptoms.

 Diagnosing medical conditions: urinary tract infection, kidney infection, kidney

stones, uncontrolled diabetes (high blood sugars), kidney impairment, muscle
breakdown (rhabdomyolysis), protein in urine, kidney inflammation
(glomerulonephritis).

 Monitoring disease progression and response to therapy: diabetes related

kidney disease, kidney impairment, lupus related kidney disease, blood pressure
related kidney disease, kidney infection, protein in urine, blood in urine.

What can urinalysis results show?

Urinalysis can disclose evidence of diseases, even some that have not caused
significant signs or symptoms. Therefore, a urinalysis is commonly a part of routine
health screening.

Urinalysis is also a very useful test that may be ordered by your physician for particular
reasons. Urinalysis is commonly used to diagnose a urinary tract or kidney infection, to
evaluate causes of kidney failure, to screen for progression of some chronic conditions
such as diabetes mellitus and high blood pressure (hypertension).

It also may be used in combination with other tests to diagnose some diseases.
Examples of this include kidney stones, inflammation of the kidneys
(glomerulonephritis), or muscle break breakdown (rhabdomyolysis). Additional tests and
clinical assessment are often required to further investigate findings of urinalysis and
ultimately diagnose the causes or specific features of underlying problems. For
example, urine infection is generally diagnosed based on results of urinalysis. However,
urine culture is often ordered as a follow-up test to identify the bacteria that may be
causing the infection.

What kind of cells can be detected?

Epithelial (flat cells) and red and white blood cells may be seen in the urine.

Sometimes cells, cellular debris, and casts are seen in the microscopic urinalysis.
Epithelial cells (cells in the lining of the bladder or urethra) may suggest inflammation
within the bladder, but they also may originate form the skin and could be
contamination.

Casts and cellular debris originate from higher up in the urinary tract, such as in the
kidneys. These are material shed from kidney cell lining due to injury or inflammation
and travel down through the urinary tubes. These usually suggest an injury to the kidney
from an inflammation or lack of blood flow to the kidneys. Rarely, tumor cells can be in
the urine suggesting a urinary tract cancer.

What can the presence of red blood cells in the urine mean?

Red blood cells can enter the urine from the vagina in menstruation or from the trauma
of bladder catheterization.

A high count of red blood cells in the urine can indicate infection, trauma, tumors, or
kidney stones. If red blood cells seen under microscopy look distorted, they suggest
kidney as the possible source and may arise due to kidney inflammation
(glomerulonephritis). Small amounts of red blood cells in the urine are sometimes seen
young healthy people and usually are not indicative of any disease.

What can the presence of white blood cells in the urine mean?

Urine is a generally thought of as a sterile body fluid, therefore, evidence of white blood
cells or bacteria in the urine is considered abnormal and may suggest a urinary tract
infection such as, bladder infection (cystitis), infection of kidney (pyelonephritis). White
blood cells may be detected in the urine through a microscopic examination (pyuria or
leukocytes in the blood). They can be seen under high power field and the number of
cells are recorded (quantitative).

White cells from the vagina or the opening of the urethra (in males, too) can
contaminate a urine sample. Such contamination aside, the presence of abnormal
numbers of white blood cells in the urine is significant.