BLOOD TESTSGroup D

About BLOOD…….

Why blood tests are carried out?

For a number of reasons;

to diagnose or rule out certain conditions

to monitor an existing condition

to find out what your blood group is before you have a transfusion

etc …

Can I eat and drink before a blood test?

You should tell if there is anything that patient need to do in preparation.

In most cases, will be able to eat and drink as normal before having a blood test.

Can I eat and drink before a blood test?

There are times not to be able to eat before a blood test, and also be asked not to drink certain liquids, tea, coffee, alcohol and fruit juice This is because eating or drinking certain

foods and liquids may affect the accuracy of certain types of blood test.

Patient is not allowed to get foods FBS Cholesterol test HIV Liver Profile for hepatitis A or B Cancer test

Complete blood count (CBC)

Red blood cell count (RBC)

White blood cell count (WBC)

Platelet count

Red blood cell count (RBC)

RBC signifies the number of red blood cells in a volume of blood.

Normal range between 4.2 to 5.9 million cells/cmm. In International units as 4.2 to 5.9 x 1012 cells per liter.

This can also be referred to as the erythrocyte count. 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.

Low Red Blood Cell Count

What does it mean? anemia malnutrition chronic inflammation acute or chronic blood loss

Nutritional deficiencies including those of; Iron Copper vitamin B12 vitamin B6

Low Red Blood Cell Count Symptoms

Fatigue and weakness due to low transport of oxygen to organs and tissues

Dizziness due to low supply of oxygen to brain

Pale skin and nails due to lack of hemoglobin

Shortness of breath Chest pain

due to the heart not receiving ample amount of oxygen Headache Feeling cold or experiencing numbness in hands or feet

As the brain is cut off its full supply of oxygen, concentration is also affected.

White blood cell count (WBC)

WBC is the number of white blood cells in a volume of blood.

Normal range between 4,300 and 10,800 cells per cubic millimeter (cmm).

In International units as 4.3 to 10.8 x 109 cells per liter.

The cells in a differential count are ; Granulocytes Lymphocytes Monocytes Eosinophils

These components can also be counted under the microscope on a glass slide.

Platelet count The number of platelets in a specified volume of

blood.

Normal range 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.

Blood Test : Blood Cultures A sample of blood from a vein is taken (venipuncture). Through special laboratory procedures, the blood is incubated over

night. If bacteria are present in the blood specimen, they will grow in the laboratory and be identified.

Using the information derived from the blood culture, it is possible to determine the most appropriate antibiotic for treatment of the patient's infection. Patients who require blood cultures are often admitted to the hospital (pending final culture results, in 24-48 hours).

Here are some instances where blood cultures are performed: Any patient thought to have a blood borne infection (pneumonia,

meningitis, and sepsis). Infants under 2 years of age with fever. This age group is at much greater

risk for a blood borne infection, particularly in the presence of high fever (sepsis).

Elderly patients with an unknown source of fever. Any immunocompromised patient who runs a fever: AIDS patient, diabetic

patient, or the cancer patient on chemotherapy.

Erythrocyte Sedimentation Rate

ESR/Sedimentation Rate/Biernacki Reaction rate at which red blood cells sediment in a period of 1

hour

To perform the test; anticoagulated blood is placed in an upright tube, known

as a Westergren tube, and the rate at which the red blood cells fall is measured and reported in mm/h.

The ESR is governed by the balance between pro-sedimentation factors Fibrinogen negative charge of the erythrocytes (zeta potential)

ESR

When an inflammatory process is present, the high proportion of fibrinogen in the blood causes red blood cells to stick to each other.

The red cells form stacks called 'rouleaux' which settle faster.

Rouleaux formation can also occur in association with some lymphoproliferative disorders in which one or more immunoglobulin/s is/are secreted in high amounts.

Rouleaux formation can, however, be a normal physiological finding in horses, cats, and pigs.

Hemoglobin (Hb)

Normal range for hemoglobin is different between the sexes MEN : 13 to 18 grams per deciliter WOMEN : 12 to 16 grams per deciliter

In International units (millimoles/liter) MEN : 8.1 to 11.2 WOMEN : 7.4 to 9.9

Hematocrit (Hct) Hct = volume of red cells volume of whole blood

Normal range Men : 45% to 52% Women : 37% to 48%

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.

Polycythemia is considered when the hematocrit is greater than 48% in women and 52% in men.

•Hematocrit (HCT): Polycythemia is considered when the hematocrit is greater than 48% in women and 52% in men. •Hematocrit (HCT): Polycythemia is considered when the hematocrit is greater than 48% in women and 52% in men.

Mean corpuscular volume (MCV)

Average volume of a red blood cell

This is a calculated value derived from the hematocrit and red cell count.

Normal range between 80 to 100 femtoliters (a fraction of

one millionth of a liter)

Mean Corpuscular Hemoglobin (MCH)

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 27 to 32 picograms

Mean Corpuscular Hemoglobin Concentration (MCHC)

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 32% to 36%

Red Cell Distribution Width (RDW)

Measurement of the variability of red cell size and shape.

Higher numbers indicate greater variation in size.

Normal range 11 to 15

Blood Test : Glucose

Glucose is the main energy source for all body tissues. The food we eat is ultimately broken down into this essential form which is utilized by every living cell.

Blood glucose levels can be measured in a number of ways: FASTING BLOOD SUGAR - Your doctor will ask you not to eat for a 12-14

hour period before the blood sample is taken. Glucose levels should be within a normal range. A higher level may indicate diabetes. Fasting blood sugar levels are also useful to monitor known diabetics. Approximate NORMAL FASTING GLUCOSE: 70 to 110 milligrams per deciliter of blood.

TWO HOUR POSTPRANDIAL SUGAR - The blood sample is taken 2 hours after the patient eats a normal meal. This test is useful for monitoring diabetics and regulating their insulin requirements. Approximate NORMAL 2-HOUR POSTPRANDIAL GLUCOSE: 120 to 150 milligrams per deciliter.

RANDOM BLOOD SUGAR - Drawn at any time, with no special requirements. This test is often done on an emergent basis to evaluate the symptomatic patient (unconscious patient). Approximate normal values vary from 110 to 200.

Glucose Tolerance Test (GTT)

Tests how the body breaks down (metabolizes) sugar

How the Test is Performed ? oral glucose tolerance test (OGTT)

intravenous glucose tolerance test (IGTT)

Why the Test is Performed

Cushing syndrome

Diabetes

Gestational diabetesbetween 24 and 28 weeks

Normal Results

Normal blood values for a 75-gram OGTT used to check for type 2 diabetes: Fasting: 60 -100 mg/dL 1 hour: less than 200 mg/dL 2 hours: less than 140 mg/dL.

Between 140 - 200 mg/dL is considered impaired glucose tolerance (sometimes called "prediabetes"). This group is at increased risk for developing diabetes.

Greater than 200 mg/dL is a sign of diabetes mellitus.

Normal Results

Normal blood values for a 50-gram OGTT used to screen for gestational diabetes: 1 hour: equal to or less than 140 mg/dL

Normal blood values for a 100-gram OGTT used to screen for gestational diabetes: Fasting: less than 95 mg/dL 1 hour: less than 180 mg/dL 2 hour: less than 155 mg/dL 3 hour: less than 140 mg/dL

Factors that may affect the test results:

Acute stress (for example, from surgery or an infection)

Vigorous exercise Several drugs may cause glucose

intolerance, including: Beta-blockers (for example, propranolol) Certain psychiatric medications Corticosteroids (for example, prednisone) Oral contraceptives (birth control pills) Thiazide diuretics (for example,

hydrochlorothiazide)

Blood Test : Liver Profile

The liver profile produces a quantitative measurement of the liver enzymes in the blood stream.

These enzymes are typically present in the blood within certain normal ranges.

The liver profile is performed from a venipuncture specimen.

Normal Values Alkaline Phosphatase (Alk Phos)..............20-90

international units per liter

Elevated in cases of ;

Hepatitis Gallbladder disease Alcohol abuse Paget's disease Bone tumors Some cancers Drug side effect

Bilirubin Test

Bilirubin is a yellowish pigment found in bile, a fluid produced by the liver.

Test done to measure bilirubin in the blood.

Hemoglobin Heme Globin Heme + Albumin Liver

Heme Fe2+

Biliverdin Bilirubin Bilirubin + Bile Conjugated

bilirubin Bilirubin Unconjugated bilirubin

Conjugated bilirubin + Unconconjugated bilirubin = Total bilirubin

Normal Values

Bilirubin (total)................................0.1 to 1.2 milligrams per deciliter

Elevated in cases of ;

Ethanol induced liver disease Hepatitis Hemolytic anemia Mononucleosis Drug side effects Gallbladder disease

What Abnormal Results Mean?

Jaundice is a yellowing of the skin and the white part of the eye. a level greater than approximately 2.5 mg/dL.

Increased indirect or total bilirubin may be a sign of:

Crigler-Najjar syndrome Erythroblastosis fetalis Gilbert's disease Healing of a large hematoma (bruise or bleeding under the skin) Hemolytic anemia Hemolytic disease of the newborn Hepatitis Physiological jaundice (normal in newborns) Sickle cell anemia Transfusion reaction Pernicious anemia

What Abnormal Results Mean?

Increased direct bilirubin may indicate: Bile duct obstruction Cirrhosis Dubin-Johnson syndrome (very rare) Hepatitis Intrahepatic cholestasis (buildup of bile in the

liver) due to any cause

Normal Values

Serum Glutamic Oxalacetic Transaminase (SGOT)...10-40 international units per deciliter

Elevated in cases of ; Hepatitis Some cases of mononucleosis Secondary to drugs or alcohol

Since it is also present in cardiac muscle, it can be elevated in the case of Myocardial infarction

Normal Values

Serum Glutamic Pyruvic Transaminase (SGPT) ...... 10 -30 international units per deciliter

Elevated in cases of ;

Hepatitis Some cases of mononucleosis Secondary to drugs or alcohol

Normal Values

Gamma Glutamyl Transpeptidase (GGT)......0-45 international units per deciliter

Elevated in cases of ;

Hepatitis Mononucleosis Drug side effects

Thyroid Profile

Conditions where the thyroid profile is useful: SUSPECTED HYPERTHYROIDISM SUSPECTED HYPOTHYROIDISM SUSPECTED THYROID CANCER PATIENTS ON THYROID SUPPLEMENTS (Synthroid) NEWBORNS (general screening purposes)

Thyroid hormones are normally present in the bloodstream in minute quantities.

Active thyroid hormone is referred to as T4. An inactive form of thyroid hormone, known as T3, is

eventually converted by the body to the active form, T4. Thyroid stimulating hormone (TSH) is produced by the

pituitary gland. This hormone stimulates the thyroid to produce more active thyroid hormone.

Normal Values

TOTAL T3 80-220 ng/dl

TOTAL T4 5-13 ug/ml

TSH .55-3.89 ugIU/ml

Kidney Profile

This test measures (quantitatively) amount of

waste products in the blood. The kidney profile is an important test that can

diagnose not only kidney disease, but also severe dehydration.

Patients with consistently abnormal kidney profiles, despite good hydration (fluid intake), may require additional tests to determine the exact extent of kidney malfunction.

This is also a routine screening test, prior to surgery.

Approximate normal values

Blood Urea Nitrogen (BUN).......8 to 23 grams per deciliter

Elevations seen in; kidney disease Dehydration kidney stone with urinary obstruction urine retention Starvation astrointestinal bleeding

Creatinine (Cr)...................0.6 to 1.2 milligrams per deciliter

Elevations seen in; kidney disease

CRP Test

What is C-reactive protein (CRP)? C-reactive protein (CRP) is a blood test marker for

inflammation in the body.

CRP is produced in the liver CRP is classified as an acute phase reactant,

which means that its levels will rise in response to inflammation.

Other common acute phase reactants include; the erythrocyte sedimentation rate (ESR) blood platelet count

What are the main causes of an elevated C-reactive protein?

In general, the main causes ; trauma Burns Infections

Elevated C-reactive protein (CRP) a risk factor for cardiovascular disease?

Because of the inflammatory component of atherosclerosis, elevated CRP level has been linked with cardiovascular disease.

However, based on the current available data it cannot be considered an independent risk factor for cardiovascular disease.

Traditional risk factors for cardiovascular disease

High blood pressure (hypertension) Diabetes mellitus Elevated blood cholesterol Age Cigarette smoking Obesity Family history of heart disease

May correlate with an elevated CRP level

How is C-reactive protein (CRP) measured?

By veinipuncture The traditional CRP measurement is often used

to detect inflammation in the body. Currently, a more highly sensitive measurement

to detect CRP (hsCRP ) is used for cardiovascular risk assessment.

Testing

Increased levels are observed, after a heart attack in sepsis after a surgical procedure

Its rise in the blood can also precede pain, fever, or other clinical indicators.

The level of CRP can jump a thousand-fold in response to inflammation and can be valuable in monitoring disease activity.

Why It Is Done?

Check for infection after surgery. CRP levels normally rise within 2 to 6 hours of surgery and

then go down by the third day after surgery. If CRP levels stay elevated 3 days after surgery, an infection

may be present.

Identify and keep track of infections and diseases that cause inflammation, such as: Cancer of the lymph nodes (lymphoma) Diseases of the immune system, such as lupus Painful swelling of the blood vessels in the head and neck (giant cell

arthritis) Painful swelling of the tissues that line the joints (rheumatoid

arthritis) Swelling and bleeding of the intestines (inflammatory bowel disease) Infection of a bone (osteomyelitis)

BLOOD TEST : Hepatitis Screen

The diagnosis of VIRAL HEPATITIS may be made with this simple blood test.

Viral hepatitis includes 3 types, and all are detectable by this test: HEPATITIS A HEPATITIS B HEPATITIS C

This blood test will show the doctor which type of hepatitis is present and whether it is a recent, or an old infection (you had it in the past)

Hepatitis screening measures the level of antibody the body has produced in response to the viral infection.

It is important to diagnose viral hepatitis to limit the spread of this contagious disease.

This is particularly important in the routine testing of potential blood donors.

The test is performed as a routine venipuncture specimen and will usually take 2-3 days to receive the results.

Blood Test : Amylase

Amylase is a digestive enzyme found in the salivary glands, liver, fallopian tubes, and pancreas.

Inflammation of the liver, pancreas, or salivary glands will cause amylase to be released into the bloodstream in increased quantities.

This test is useful in diagnosing:

Pancreatitis (elevated amylase) Hepatitis (inflammation of liver leads to elevated amylase) Gallbladder disease (here, the gallbladder causes secondary

inflammation of the pancreas and elevated amylase)

Blood Test : Amylase Cont…..

This test is useful in diagnosing:

Mumps or Parotitis (inflammation of a salivary gland causes an elevated amylase)

Pancreatic Cancer (elevated amylase) Ruptured Tubal Pregnancy (elevated amylase) Perforated Peptic Ulcer (elevated amylase) Drug Side Effect (e.g. alcohol, Demerol)

This test is also useful in evaluating patients with abdominal pain of unknown origin.

This test is performed using a standard venipuncture specimen.

APPROXIMATE NORMAL VALUE 60-160 Somogyi units per deciliter

Arterial blood gases

This special test requires arterial blood (oxygenated). In the arterial blood gases test, a blood specimen is generally taken from the wrist or arm in a manner similar to a routine venipuncture

The arterial blood gas test will indicate, the acid/base balance of the body oxygen content of the blood assess the effectiveness of the patient's breathing

Using this information, the physician can make important therapeutic decisions (i.e. does the patient need oxygen? Will the patient require

assisted mechanical ventilation?). These important questions can only be answered with the

results of this valuable test.

Arterial blood gases

Arterial blood gases are commonly performed in patients with: Congestive heart failure (low p02) Pulmonary embolism (low pO2) Asthma (low p02, low pH, and high pC02) Chronic obstructive pulmonary disease

(smokers) (low p02 and high pC02) Pneumonia (low p02) Diabetic ketoacidosis (low pH and low pC02) Unexplained breathing difficulty

Normal Values

Partial pressure of oxygen (pO2) 80-100 mm Hg

Partial pressure of carbon dioxide (pC02) 35-45 mm Hg

pH 7.38-7.44

O2 saturation 95-100%

Bicarbonate 22-25 meq/l

Ex; If you stop or severely slow your breathing: pH will go down, pC02

will increase, and p02 will decrease. If you hyperventilate: pH will increase, p02 will increase, and pC02

will decrease.

Blood Test : Coagulation Profile

Measures the interval of time for several stages of the blood clotting cycle.

Values are reported in seconds (the time it takes for the blood to clot). Also referred to as the PROTHROMBIN TIME (PT) and PARTIAL THROMBOPLASTIN TIME (PTT), these tests give the doctor information pertaining to liver function (the liver produces clotting factors needed to make blood coagulate).

Conditions where the coagulation profile is of importance include: Assessment of liver function

As a pre-operative screening test before surgery

To follow and maintain adequate anti-coagulation in those patients taking anti-coagulants (coumadin).

Establishing baseline coagulation in patients being considered for anticoagulation therapy.

Testing coagulation in patients with a disease process known to interfere with coagulation.

APPROXIMATE NORMAL VALUES

Prothrombin Time (PT)..........11.0 to 12.5 seconds (results vary with regard to controls). Elevated above normal in patients taking blood thinners

(Coumadin) or in those who are vitamin K deficient. Therapeutic anticoagulation is often approximately 1.5 times the normal prothrombin time (or a PT of about 17-18).

Partial Thromboplastin Time (PTT).....25 to 50 seconds (results vary with regard to controls). Elevated in some cases of severe liver disease (cirrhosis).

Blood Test : SMAC-25

This test is a useful combination of electrolyte, kidney profile, and liver profile data.

Additional tests found in the SMAC-25 (tests can differ from lab to lab) screen for levels of calcium, magnesium, phosphate, cholesterol, triglycerides, and others.

The SMAC-25 is useful as a general screening tool and is performed on a yearly basis by many internists.

This test is usually cheaper to run as a "SMAC" then as a sum total of the separate lab tests.

The SMAC is occasionally used as a preoperative screening test. This test is run on a venipuncture specimen. See values below.

SMAC 25 NORMAL VALUES

GLUCOSE 70-110 mg/dl BUN (urea nitrogen) 8-23 mg/dl NA (sodium) 136-142 meq/l K (potassium) 3.8-5.0 meq/l CL (chloride) 95-103 meq/l CO2 (carbon dioxide) 22-38 millimoles/l CR (creatinine) .6-1.5 mg/dl URC (uric acid) 2-8 mg/dl CA (calcium) 8.5-10.5 mg/dl PHOS (phosphorus) 2.5-4.5 mg/dl TP (total protein) 6.0-8.0 g/dl ALB (albumin) 3.5-5.0 g/dl

SMAC 25 NORMAL VALUES

TBILI (total bilirubin) 0.1-1.2 mg/dl ALP (alkaline phosphatase) 20-90 IU/dl GT (gama glutamyl transpeptidase) 0-45 IU/dl SGPT (ALT) 0-30 IU/dl LDH (lactate dehydrogenase) 60-200 IU/dl SGOT (AST) 10-40 IU/dl CK (creatine phosphokinase) 30-150 IU/dl CHOL (cholesterol) see test file chart TRIG (triglycerides) 10-150 mg/dl AMYL (amylase) 60-160 SU/dl LAC (lactic acid) 3-24 meq/dl MG (magnesium) 3-2.4 mg/dl

NOTE: The above normal values can vary slightly from lab to lab

The values and what they mean

Glucose: Abnormal elevations in the blood glucose

can as the result of; diabetes medication side effects (e.g. thiazide diuretics,

steroids).

BUN (blood urea nitrogen): Abnormal elevations

dehydration starvation fever kidney disease high protein diets drug side effects kidney stone with obstruction acute urinary retention gastrointestinal bleeding

Abnormally low values can be seen in liver disease malnutrition excessive fluid intake

NA - sodium

Elevations can be seen in ; some cases of dehydration drug side effects excessive dietary salt some glandular disorders (Cushing's disease)

Low Na levels can also be seen in; some cases of dehydration (vomiting) CHF glandular disorders (Addison's disease) drug side effects kidney disease severe lung disease

K - potassium

Abnormal elevations in; kidney disease diabetic ketoacidosis Addison's disease liver disease drug side effects severe burns crush injuries electrical injuries excessive use of potassium supplements (or salt substitutes)

Abnormally low potassium levels can be seen in Cushing's disease diarrhea diuretic use excessive vomiting inadequate dietary intake

C02 - carbon dioxide

Abnormal elevations in C02

cases of severe COPD Cushing's disease excessive antacid use drug side effects (steroid and diuretic use)

Low levels can be seen ; diabetic ketoacidosis kidney failure severe diarrhea aspirin overdose sepsis (bacteria in the bloodstream) shock.

CR - creatinine

Abnormal elevation; secondary to kidney disease, dehydration, diabetic ketoacidosis

Abnormally low levels can be seen with malnutrition.

URC - uric acid

An abnormal elevation; some (but not all) patients with gout Leukemia multiple myeloma chemotherapy

In the uric acid level in the bloodstream can be seen in radiation therapy for cancer metabolic defects toxemia of pregnancy fever Some medications (thiazide diuretics, furosemide, ethacrynic acid,

probenecid, corticosteroids, aspirin)

Low uric acid levels can be found in some forms of kidney disease and as a drug side effect (allopurinol)

CA - calcium

Elevations hyperparathyroidism multiple myeloma cancers with spread to bone excessive vitamin D intake excessive use of antacids which contain calcium (e.g. Rolaids) drug side effect prolonged bedrest

Abnormally low calcium levels serum albumin Hypoparathyroidism low vitamin D intake pregnancy osteomalacia certain kidney diseases

Phosphorus

Abnormal elevations kidney disease hypoparathyroidism healing fractures excessive vitamin D intake

Abnormally low levels hyperparathyroidism vitamin D deficiency alcoholism

Total protein Abnormal elevations

multiple myeloma dehydration vomiting or diarrhea

Low levels Malnutrition CHF toxemia of pregnancy

Albumin: Decreased levels liver disease some forms of kidney disease.

Creatine phosphokinase

Elevations after sustaining a crush injury to muscle tissue after strenuous exercise myocardial infarction (see cardiac enzymes) rhabdomyolysis (from an electrical injury or

alcohol abuse) polymyositis (inflammatory muscle disease) polymyalgia rheumatica

Magnesium

Elevations kidney failure dehydration

Low levels alcoholism malnutrition drug side effects Pancreatitis hyperthyroidism hyperparathyroidism

Lactate dehydrogenase(LDH)

This enzyme is present in brain, liver, muscle, heart, bone, and lung.

Disease processes in any of these organs can lead to elevation in the blood LDH.

Spread of cancer to the bones or liver can result in the elevation of the LDH.

Mononucleosis Test or Monospot

Mononucleosis is a common, nonserious viral disease which causes a wide variety of symptoms.

The monospot test involves mixing reagents with a drop of blood on a microscope slide.

Results of the test are read, usually in less than one hour, as positive (you have the disease) or negative.

Because the test may be negative in the early part of the illness, it must be repeated later if symptoms persist.

Mononucleosis is often confused clinically with strep throat because of their similar appearance on physical examination of the pharynx (throat).

This test is performed by means of a venipuncture specimen.

Pregnancy Test

This is a test for detecting a particular hormone known as HUMAN CHORIONIC GONADOTROPIN (HCG).

The HCG blood test may be reported as positive (pregnant), or as a quantitative value, which can be used to estimate the gestational age of the fetus.

HCG, which is excreted into the urine, is the basis for the home urine pregnancy test.

Unlike the urine test, the blood test can detect pregnancies as early as 7 days after fertilization (even before a missed menstrual period!).

It is important to note that certain rare tumors also secrete HCG.

The HCG blood test has also been used to assess the effectiveness of treatment in these tumor patients.

Mothers with twins will normally have correspondingly higher HCG levels.

This test is performed from a venipuncture specimen.

HIV Antibody

Also known as: AIDS test AIDS screen HIV serology

Formal name: Human immunodeficiency virus antibody test

Recommend that anyone over the age of 13 be screened for HIV.

Antibody testing for HIV is especially important if you are in a high risk group or if you think you may have been exposed to HIV.

When is it ordered?

Testing is recommended if:

You are sexually active (three or more sexual partners in the last 12 months).

You received a blood transfusion prior to 1985, or a sexual partner received a transfusion and later tested positive for HIV.

You are uncertain about your sexual partner’s risk behaviors.

You are a male who has had sex with another male.

Testing is recommended if: You have used street drugs by injection, especially when

sharing needles and/or other equipment.

You have a sexually transmitted disease (STD).

You are a health care worker with direct exposure to blood on the job.

You are pregnant. (There are now treatments that can greatly reduce the risk that a pregnant woman who has HIV will give the virus to her baby.)

You are a woman who wants to make sure you are not infected with HIV before getting pregnant.

Allergy Blood Test

Also known as: RAST test Radioallergosorbent test Allergy screen

Formal name: Allergen-specific IgE antibody test

Related tests: Total IgE Complete blood count (CBC) White blood cell differential count

How is it used? The allergen-specific IgE antibody test is a blood test used to screen for an

allergy to a specific substance or substances if a person presents with acute or chronic allergy-like symptoms.

The usefulness of these tests, however, can be affected by skin conditions, significant dermatitis or eczema, by medications, such as histamines some anti-depressants With some tests there is also the potential for severe reactions, including

a severe reaction that may be life-threatening. In these cases, the allergen-specific IgE antibody test may be ordered as an alternative, as it is performed on a blood sample and does not have an effect on the person being tested.

The allergen-specific IgE antibody test may also be done to monitor immunotherapy (desensitization) or to see if a child has outgrown an allergy. It can only be used in a general way, however, as the level of IgE present does not correlate to the severity of an allergic reaction, and someone who has outgrown an allergy may have a positive IgE for many years afterward. How is it used

When is it ordered? One or more allergen-specific IgE antibody tests are

usually ordered when a person has signs or symptoms that suggest an allergy to one or more substances. Signs and symptoms may include: Hives

Dermatitis Eczema Red itchy eyes Coughing, nasal congestion, sneezing Asthma Itching and tingling in the mouth Abdominal pain, or vomiting and diarrhea

What does the test result mean? Negative results indicate that a person probably does not

have a "true allergy," an IgE-mediated response to that specific allergen, but the results of allergen-specific IgE antibody tests must always be interpreted and used with caution and the advice of the doctor. Even if an IgE test is negative, there is still a small chance that a person does have an allergy. Elevated results usually indicate an allergy, but even if the specific IgE test is positive, a person may or may not ever have an actual physical allergic reaction when exposed to that substance. The amount of specific IgE present does not necessarily predict the potential severity of a reaction. A person's clinical history and additional medically supervised allergy tests may be necessary to confirm an allergy diagnosis.

Fasting Blood Glucose (Blood Sugar) Level

The gold standard for diagnosing diabetes is an elevated blood sugar level after an overnight fast (not eating anything after midnight).

A value above 140 mg/dl on at least two occasions typically means a person has diabetes.

Normal people have fasting sugar levels that generally run between 70-110 mg/dL.

Cholesterol test

A cholesterol test/ lipid panel or lipid profile,

measures the fats (lipids) in the blood. The measurements can indicate risk of

having a heart attack or other heart disease.

The test typically includes measurements of:

Total cholesterol HDL LDL

TRYGLYCERIDES

Total cholesterol

. This is a sum of your blood's cholesterol content.

A high level can put you at increased risk of heart disease.

Ideally, total cholesterol should be below 200 milligrams per deciliter, or mg/dL (5.2 millimoles/liter, or mmol/L).

Low-density lipoprotein (LDL) cholesterol

. This is sometimes called the "bad" cholesterol.

Too much of it in your blood causes the accumulation of fatty deposits (plaques) in your arteries (atherosclerosis), which reduces blood flow.

These plaques sometimes rupture and lead to major heart and vascular problems. Ideally, your LDL cholesterol level should be less than 130 mg/dL (3.4 mmol/L).

High-density lipoprotein (HDL)

cholesterol. This is sometimes called the "good" cholesterol because it helps carry away LDL cholesterol, keeping arteries open and your blood flowing more freely.

Ideally, your HDL cholesterol level should be 60 mg/dL (1.6 mmol/L) or higher, though it's common that HDL cholesterol is higher in women than men.

Triglycerides.

Triglycerides are another type of fat in the blood. High triglyceride levels usually mean you regularly eat more calories than you burn. High levels increase your risk of heart disease. Ideally, your triglyceride level should be less than 150 mg/dL (1.7 mmol/L)

Natriuretic peptides

Brain natriuretic peptide, also called B-type

natriuretic peptide (BNP) , is a protein that heart and blood vessels produce.

BNP helps body eliminate fluids, relaxes blood vessels and funnels sodium into urine.

When heart is damaged, your body secretes high levels of BNP into bloodstream to try to ease the strain on your heart.

BNP levels may also rise if you have new or increasing chest pain (unstable angina) or after a heart attack.

BNP level can help in the diagnosis and evaluation of heart failure and other heart conditions.

Normal levels vary according to age and gender. In general, having a BNP level of:

100 picograms per milliliter, or pg/mL or lower means it's unlikely you have heart failure.

Between 100 and 300 pg/mL may be a sign of heart failure.

Higher than 300 pg/mL means you likely have heart failure.

A variation of BNP called N-terminal BNP also is useful in diagnosing heart failure. N-terminal BNP may also be useful in evaluating your risk of heart attack and other problems if you already have heart disease.

Diabetes and the Fasting Plasma Glucose Test

The fasting plasma glucose test (FPG) is the preferred method for diagnosing diabetes because it is easy to do, convenient, and less expensive

How Do I Prepare for the Blood Glucose Test? Before taking the blood glucose test, you will not be allowed

to eat anything for at least eight hours.

What Do the Results of the Blood Glucose Test Mean? Normal fasting blood glucose -- or blood sugar -- is between

70 and 100 milligrams per deciliter or mg/dL for people who do not have diabetes.

The standard diagnosis of diabetes is made when two separate blood tests show that your fasting blood glucose level is greater than or equal to 126 mg/dL.

The Casual Plasma Glucose Test for Diabetes

The casual plasma glucose test is another method of diagnosing diabetes.

During the test, blood sugar is tested without regard to the time since the person's last meal. You are not required to abstain from eating prior to the test.

A glucose level greater than 200 mg/dL may indicate diabetes, especially if the test is repeated at a later time and shows similar results.

The different types of HIV test

Using a rapid oral HIV test HIV antibody test HIV antibody tests are the most appropriate test for routine diagnosis of

HIV among adults.   Antibody tests are inexpensive and very accurate. The ELISA antibody test (enzyme-linked immunoabsorbent) also known

as EIA (enzyme immunoassay) was the first HIV test to be widely used. How do antibody tests work? When a person is infected with HIV, their body responds by producing

special proteins that fight infection, called antibodies. An HIV antibody test looks for these antibodies in blood, saliva or urine. If antibodies to HIV are detected, it means a person has been infected with HIV. There are only two exceptions to this rule:

Babies born to HIV infected mothers retain their mother's antibodies for up to 18 months, which means they may test positive on an HIV antibody test, even if they are actually HIV negative. Normally babies who are born to HIV positive mothers receive a PCR test (see below) after birth.

Antigen test (P24 test)

Antigens are the substances found on a foreign body or germ that trigger the production of antibodies in the body.

The antigen on HIV that most commonly provokes an antibody response is the protein P24. Early in HIV infection, P24 is produced in excess and can be detected in the blood serum (although as HIV becomes fully established in the body it will fade to undetectable levels).

P24 antigen tests are not usually used for general HIV diagnostic purposes, as they have a very low sensitivity and they only work before antibodies are produced in the period immediately after HIV infection. They are now most often used as a component of 'fourth generation' tests.

How do I get a paternity test?

A paternity test involves looking at the DNA of a child in order to check the identity of his or her father.

DNA is the genetic code that you inherit from both your parents which gives your body instructions about your features (such as the colour of your eyes).

Paternity tests are sometimes carried out when a woman has had more than one sexual partner around the time she conceived (got pregnant) or because the father of the child is denying that the child is his.

Sometimes, paternity tests are requested by the court which is known as court-directed. This means that paternity needs to be provided as evidence in a legal case.

How the paternity test is performed

A simple test, using the blood types of both parents and the child, can help to rule out a particular man as the father.

But to completely prove paternity, scientists need to examine samples of DNA.

This used to be done by testing blood samples, but now most tests involve using a swab to take some samples of cells from the inside of the cheek.

The child, the mother, and the assumed father must provide the same type of sample (blood samples or cheek cells). By examining the individual genetic markers in DNA, scientists can give an answer that is more than 99% accurate.

Fibrinogen test

Fibrinogen is a protein in your blood that helps blood clot. But too much fibrinogen can cause a clot to form in an artery, leading to a heart attack or stroke.

Having too much fibrinogen may also mean that you have an inflammatory response that accompanies atherosclerosis. It may also worsen existing injury to artery walls.

Smoking, inactivity, excessive alcohol consumption and

supplemental estrogen — whether from birth control pills or

hormone therapy — may increase your fibrinogen level.

A normal fibrinogen level is considered to be between 200 and 400 milligrams per liter (mg/L).

Acetylcholine Receptor Antibody Test

Is an antibody found in the blood of people with myasthenia gravis.

Attacks receptors for the neurotransmitter acetylcholine, which sends signals from nerves to muscles and from nerve to nerve in the brain.

The antibody prevents transmission of the signal and causes muscle weakness.

Why the test is performed?

This is a diagnostic test for myasthenia gravis. About 85% of people with generalized myasthenia and 60% of people with ocular myasthenia will have acetylcholine receptor antibodies in their blood.

Normal Values No acetylcholine receptor antibody (or less

than .05 nmol) in the bloodstream

What abnormal results mean?

Presence of acetylcholinesterase antibody in the blood of patients with symptoms of myasthenia gravis supports the diagnosis.

About 10-15% of people with myasthenia gravis do not have evidence of antibody production.

Special considerations; Acetylcholine receptor antibody testing can confirm a diagnosis of

myasthenia

Symptoms include; weakness gets worse as they day progresses or with blurred or double vision repeated exertion nasal-sounding voice and difficulty swallowing