Laboratory Exam Normal Value Details and Indications

Complete Blood Count

RBC count (varies with altitude): o Male: 4.7 to 6.1 million

cells/mcLo Female: 4.2 to 5.4 million

cells/mcL WBC count: 4,500 to 10,000 cells/mcL Hematocrit (varies with altitude):

o Male: 40.7 to 50.3 %o Female: 36.1 to 44.3 %

Hemoglobin (varies with altitude): o Male: 13.8 to 17.2 gm/dLo Female: 12.1 to 15.1 gm/dL

MCV: 80 to 95 femtoliter MCH: 27 to 31 pg/cell MCHC: 32 to 36 gm/dL

(cells/mcL = cells per microliter; gm/dL = grams per deciliter; pg/cell = picograms per cell)

Note: Normal value ranges may vary slightly among different laboratories.

A complete blood count (CBC) is a series of tests used to evaluate the composition and concentration of the cellular components of blood.

It measures the following:

The number of red blood cells (RBCs)

The number of white blood cells (WBCs)

The total amount of hemoglobin in the blood

The fraction of the blood composed of red blood cells (hematocrit)

The mean corpuscular volume (MCV) — the size of the red blood cells

High numbers of RBCs or a high hematocrit may be due to:

Dehydration (such as from severe diarrhea)

Kidney disease with high erythropoietin production

Low oxygen level in the blood:

Polycythemia vera Smoking

Low numbers of RBCs or low hematocrit indicates anemia, which can result from:

Autoimmune/collagen-vascular diseases such as lupus erythematosus or rheumatoid arthritis

Blood loss Bone marrow failure

Erythropoietin deficiency (usually secondary to kidney disease)

Hemolysis (red blood cell destruction)

Leukemia Malnutrition Multiple myeloma

A lower-than-normal white blood cell count is called leukopenia. A decreased WBC count may be due to:

Autoimmune/collagen-vascular diseases (such as systemic lupus erythematosus)

Bone marrow failure Disease of the liver or spleen

High numbers of WBCs is called leukocytosis. It can result from:

Infectious diseases Inflammatory disease

(such as rheumatoid arthritis or allergy)

Leukemia Severe emotional or

physical stress Tissue damage (such as

burns)

Low hemoglobin values may indicate:

Anemia (various types) Blood loss

Fasting Blood Sugar

Normal fasting blood sugar levels are below 100. The normal range is between 70 to 100 mg/L (milligrams per decaliter). In Europe, the measurement is given in milileters and the corresponding numbers are 3.5 to 5.5 mmol/L.

Blood glucose tests are done to:

Check for diabetes. Monitor treatment of

diabetes. Check for diabetes that

occurs during pregnancy (gestational diabetes).

Determine if an abnormally low blood sugar level (hypoglycemia) is present. A test to measure blood levels of insulin and a protein called C-peptide may be done along with a blood glucose test to determine the cause of hypoglycemia.

Urinalysis Calcium <7.3 mmol/day

Chloride 110-250 mmol/day

Creatinine 6.2-17.7 mmol/day

Osmolality 100-1200 mOsm/kg

Potassium 25-120 mmol/day

Urinalysis performs to analyze the urine physical color and appearance, microscopic appearance, and chemical appearance.

Urine potassium may be ordered in the workup of hypokalemia. In case of GI loss of potassium, the urine

Protein<0.15 g/day

Sodium25-260 mmol/day

potassium will be low. In case of renal loss of potassium, the urine potassium levels will be high. Increased levels of potassium are also seen in hypoaldosteronism and adrenal insufficiency.

The sodium levels are frequently ordered during the workup of acute renal failure.

The presence of nitrites in urine indicate the presence of coliform bacteria.

WBC in urine are a marker of infection if present for greater than 5 wbc per high power field.

Small amounts of protein or ketoacidosis tend to elevate results of the specific gravity. Specific gravity is an expression of the weight of a substance relative to the weight of an equal volume of water.

Stool Gram stain A normal result means only normal or "friendly" bacteria were seen on the stained slide. Everyone has friendly bacteria in their intestines.

Note: Normal value ranges may vary slightly among different laboratories.

A stool Gram stain is a laboratory test that uses different stains to detect and identify bacteria in a stool sample.

The Gram stain method is sometimes used to rapidly diagnose bacterial infections.

Stool Ova and Parasites Exam

There are no parasites or eggs in the stool sample.

Normal value ranges may vary slightly among different laboratories.

Stool ova and parasites exam is a laboratory test to determine if a stool sample contains parasites or eggs (ova) that are associated with intestinal infections.

Blood Urea Nitrogen

7 - 20 mg/dL.

Note that normal values may vary among different laboratories.

The blood urea nitrogen (BUN, pronounced "B-U-N") test is a measure of the amount of nitrogen in the blood in the form of urea, and a

measurement of renal function. Urea is a substance secreted by the liver, and removed from the blood by the kidneys.

A greatly elevated BUN (>60 mg/dL) generally indicates a moderate-to-severe degree of renal failure. An elevated BUN in the setting of a relatively normal creatinine may reflect a physiological response to a relative decrease of blood flow to the kidney without indicating any true injury to the kidney.

When the ratio of BUN to creatinine (BUN:Cr) is greater than 20, the patient is suspected of having prerenal azotemia.

A low BUN usually has little significance, but its causes include liver problems, malnutrition (insufficient dietary protein), or excessive alcohol consumption.

Electrocardiogram

normal sinus rhythm o each P wave is followed by a

QRS o P waves normal for the subject o P wave rate 60 - 100 bpm with

<10% variation rate <60 = sinus

bradycardia rate >100 = sinus

tachycardia variation >10% = sinus

arrhythmia normal QRS axis normal P waves

o height < 2.5 mm in lead II o width < 0.11 s in lead II

normal PR interval o 0.12 to 0.20 s (3 - 5 small

squares)

normal QRS complex o < 0.12 s duration (3 small

squares) o no pathological Q waves o no evidence of left or right

ventricular hypertrophy normal QT interval

o Calculate the corrected QT interval (QTc) by dividing the QT interval by the square root of the preceeding R - R interval. Normal = 0.42 s.

o Causes of long QT interval

The electrocardiogram (ECG or EKG) is a diagnostic tool that measures and records the electrical activity of the heart in exquisite detail. Interpretation of these details allows diagnosis of a wide range of heart conditions. These conditions can vary from minor to life threatening.

Abnormal ECG results may be a sign of

Abnormal heart rhythms (sarrhythmias)

Cardiac muscle defect Congenital heart defect Coronary artery disease Ectopic heartbeat Enlargement of the

heart Faster-than-normal

heart rate (tachycardia) Heart valve disease Inflammation of the

heart (myocarditis) Changes in the amount

of electrolytes (chemicals in the blood)

Past heart attack Present or impending

normal ST segment o no elevation or depression

normal T wave normal U wave

heart attack Slower-than-normal

heart rate (bradycardia)

Blood Typing The A antigen, type A blood. The liquid portion of the blood (plasma) has antibodies that fight against type B blood.

The B antigen, type B blood. The plasma has antibodies that fight against type A blood.

Neither the A nor B antigen, type O blood. The plasma has antibodies that fight against both type A and type B blood

Both the A and B antigens, type AB blood. The plasma does not have antibodies against type A or type B blood.

Blood type tests are done before a person gets a blood transfusion and to check a pregnant woman's blood type. Human blood is typed by certain markers (called antigens) on the surface of red blood cells. Blood type may also be done to see if two people are likely to be blood relatives.