Explanation of Blood Studies

Comprehensive Metabolic Panel

Complete Blood Count

Additional Tests

Comprehensive Metabolic Panel

 

Glucose is a measure of sugar content in your blood.  This value is watched closely to evaluate diabetes or hypoglycemia.  This test should be performed in a fasted (no eating) state.  Your blood sugar should be between 70-100 mg/dl to be considered normal.

 

Uric Acid is a constituent in the blood that transports nitrogen in the body.  It is normally excreted in the urine to rid the body of nitrogen.  Values that are high, typically from intake of excess fructose or purines, may indicate gout, arthritis or certain kidney problems.  A low value is not clinically significant.

 

Urea Nitrogen (BUN) is a waste product of protein metabolism.  It is produced in the liver and excreted by the kidneys. When protein metabolism is not working properly, high values may occur indicating liver or kidney problems.  Low values need not always be followed with your personal physician.

 

Creatinine is a waste product produced in your muscles from the breakdown of a compound called creatine. Creatine is part of the cycle that produces energy needed to contract your muscles and it as well as creatinine are produced at a relatively constant rate. Almost all creatinine is excreted by the kidneys, so blood levels are a good measure of how well your kidneys are working. The quantity produced depends on the size of the person and their muscle mass. For this reason, creatinine concentrations will be slightly higher in men than in women and children.

 

Estimated Glomerular Filtration Rate (eGFR): The eGFR value is a calculated estimate of kidney function.  It is calculated by using the serum creatinine, patient age, ethnic background, and gender.  Values less than 60 ml/min may warrant further investigation.

 

Sodium is an ion that is important in the conduction of nerves, contraction of muscles, and functioning of cells.  It is controlled primarily by the kidneys and adrenal glands.  High levels of sodium could indicate edema and low-level dehydration.

 

Potassium is important for muscles and nerves to function properly.  It is controlled by the kidneys.  This value is watched very closely if one is taking diuretics or cardiovascular medications.  If the blood sample is not processed properly, high values may occur.

 

Chloride, like sodium, is an ion that is important in the functioning of cells.  It is primarily controlled by the kidneys and adrenal glands.  Doctors look for electrolyte and/or acid-base imbalances when checking this value.

 

Carbon Dioxide, also referred to as bicarbonate level, this is a reflection of the body's acid-base status which reflects a variety of enzymatic reactions that occur at the cellular level.  This value is affected by both pulmonary and kidney functions.  Symptoms of imbalance include weakness, confusion, prolonged vomiting, or respiratory distress.

 

Calcium is involved in many physiologic processes.  Blood calcium is tested to screen for, diagnose, and monitor a range of conditions relating to the bones, heart, nerves, kidneys, and teeth. Blood calcium levels do not directly tell how much calcium is in the bones, but rather, how much total calcium or ionized calcium is circulating in the blood.

 

Phosphorus is an essential element in the diet.  It is a major component of the mineral phase of bone and occurs in all tissues, being involved in almost all metabolic processes.   Phosphorus is controlled by the kidneys and parathyroid glands.  Processing errors may affect this value.

 

The Total Protein test is a rough measure of all of the proteins in the plasma portion of your blood. Proteins are important building blocks of all cells and tissues; they are important for body growth and health. Total protein measures the combined amount of two classes of proteins, albumin and globulin.  Total protein measurements can reflect nutritional status, kidney disease, liver disease, and many other conditions. If total protein is abnormal, further tests must be performed to identify which protein fraction is abnormal, so that a specific diagnosis can be made.  Prolonged application of a tourniquet can also increase protein concentrations.

 

Albumin is a protein that is a carrier of many small molecules, but its main purpose is to keep fluid from leaking out of blood vessels.

 

Globulin is a protein that is insoluble in water and transported in the serum.  Globulin proteins include enzymes, antibodies, and more than 500 other proteins.

 

A/G Ratio The ratio of albumin to globulin (A/G ratio) is calculated from values obtained by direct measurement of total protein and albumin. It represents the relative amounts of albumin and globulins.  A low A/G ratio may reflect overproduction of globulins (such as seen in multiple myeloma or autoimmune diseases) or underproduction of albumin (such as occurs with cirrhosis) or selective loss of albumin from the circulation (as occurs with nephrotic syndrome). A high A/G ratio suggests underproduction of immunoglobulins (as may be seen in some genetic deficiencies and in some leukemias). More specific tests, such as albumin, liver enzyme tests, and serum protein electrophoresis must be performed to make an accurate diagnosis.

 

Total Bilirubin is a bile pigment.  When bilirubin levels are high, a condition called jaundice occurs, and further testing is needed to determine the cause. Too much bilirubin may mean that too much is being produced, usually due to increased destruction of red blood cells (hemolysis).  It may also mean that the liver is incapable of adequately removing bilirubin in a timely manner due to blockage of bile ducts, liver diseases (such as cirrhosis, acute hepatitis), or inherited problems with bilirubin handling.

 

Alkaline Phosphatase is an enzyme found primarily in bones and the liver.  Values for pregnant women, those with bile duct obstruction or Celiac disease have been found to be elevated, however low values are probably not significant.

 

LDH stands for lactate dehydrogenase. It is an enzyme involved in the breakdown of lactic acid.  Anything which causes cellular damage, including heart attacks, liver disease, and blood drawing itself, may cause higher values.

 

AST (SGOT) stands for serum glutamic oxaloacetic transaminase.  SGOT is a liver enzyme involved in cellular functions of the heart muscle and liver.  Alcohol consumption, liver disease, and other normal factors have been shown to raise this value.  Low values are probably not clinically significant.

 

ALT (SGPT) stands for serum glutamic pyruvic transaminase.  SGPT, like SGOT, is an enzyme involved in the functions of heart, liver, and muscle cells.  Alcohol consumption, liver disease, and other normal factors have been shown to raise this value.  Low values are probably not clinically significant.

 

GGT (GGTP) stands for Gamma Glutamyl Trans Peptidase. Similar to SGOT and SGPT is an enzyme involved in the function of heart, liver, and muscle cells.  If the cells are injured, this enzyme will be released into the system.  Alcohol consumption, liver disease, heart attacks, and other normal factors have been shown to raise this value.  Low values are probably not significant.

 

Cholesterol is used to make essential body substances, such as cell walls and hormones.  High levels of cholesterol have been associated with an increased risk for heart disease.  Low levels of cholesterol are good and need not be evaluated by your personal physician.

 

Triglycerides are blood fats that are the usual storage form of lipids in the body.  This value can be dramatically affected by a recent meal, thus an eight hour fast is required for accurate results.  Low values have not been found to be clinically significant.

 

HDL-Cholesterol is a high density lipoprotein, which is commonly referred to as the "good" cholesterol.  HDL-Cholesterol is a transport protein, which carries cholesterol away from the vessel wall for removal from the body.  The higher the HDL value, the lower the risk of coronary artery disease.  Exercise and weight loss has been shown to increase your HDL level, while smoking has been shown to decrease it.

 

VLDL Cholesterol is the body’s fat transportation mechanism and is considered one of the bad cholesterol.  This value is not clinically measured, but rather the triglycerides value divided by five.  Low values are not clinically significant.

 

LDL-Cholesterol is a low density lipoprotein, which is commonly referred to as the "bad" cholesterol.  LDL-Cholesterol is a transport protein that carries cholesterol from the liver to the arteries, where it is ultimately deposited.  LDL is a calculated value:  Total Cholesterol – HDL – (Triglycerides/5).  This calculation becomes inaccurate if your triglycerides are over 400.

 

Cholesterol/HDL Ratio is a ratio of total cholesterol to HDL-cholesterol, or simply a ratio of bad cholesterol to good cholesterol.  This ratio has been shown to be one of the best predictors of coronary risk, with the lower the ratio the better.  A combination of regular aerobic exercise and good nutritional practices has been shown to improve this ratio.

 

LDL/HDL Ratio is a ratio of bad to good cholesterol.  Lower values are correlated with lower risk for heart disease.

Complete Blood Count

 

WBC stands for white blood cell count. This value represents your immune system. Recent colds or infections may cause this value to be high or low.

 

RBC stands for red blood cell count. These cells carry oxygen in the blood. Low values are commonly seen in individuals with certain types of anemia.

 

Hemoglobin (HgB) is the oxygen carrying component in the red blood cell. It is formed in the bone marrow. Low values are commonly seen in individuals with certain types of anemia.

 

Hematocrit (Hct) is the volume (percentage) of red blood cells in whole blood. Low values are commonly seen in individuals with certain types of anemia.

 

MCV stands for mean cell volume. This is a measure of the average size of the red blood cells.

 

MCH stands for mean cell hemoglobin. This value represents the mean hemoglobin in each red blood cell.

 

MCHC stands for mean cell hemoglobin concentration. This value represents the mean hemoglobin concentration in each red blood cell.

 

RDW stands for Red Cell Distrubution Width.  RDW is a calculation of the variation in the size of your RBCs. In some anemias, such as pernicious anemia, the amount of variation (anisocytosis) in RBC size (along with variation in shape – poikilocytosis) causes an increase in the RDW.

 

Platelets are disk shaped structures found in the blood, primarily known for their role in the coagulation process.

 

Neutrophils is a cross-sectional look at the different kinds of white blood cells. This is a more sophisticated look at the immune system and can help identify different types of infections.

 

Lymphocytes is a cross-sectional look at the different kinds of white blood cells. This is a more sophisticated look at the immune system and can help identify different types of infections.

 

Monocytes is a cross-sectional look at the different kinds of white blood cells. This is a more sophisticated look at the immune system and can help identify different types of infections.

 

Eosinophils is a cross-sectional look at the different kinds of white blood cells. This is a more sophisticated look at the immune system and can help identify different types of infections.

 

Basophils is a cross-sectional look at the different kinds of white blood cells. This is a more sophisticated look at the immune system and can help identify different types of infections.

 

White blood cell differential looks at the types of white blood cells present. There are five different types of white blood cells, each with its own function in protecting us from infection. The differential classifies a person's white blood cells into each type: neutrophils (also known as segs, PMNs, grans), lymphocytes, monocytes, eosinophils, and basophils.

 

Additional Tests

 

PSA stands for Prostate Specific Antigen.  It is used to screen for the presence of prostate cancer.  Normally most of the PSA remains in the prostate gland and very little is released into the blood stream.  When there are diseased or cancerous cells present in the prostate gland more PSA leaks out into the blood stream.  While the normal range for PSA is any value below 4.0 ng/ml, another factor to consider is PSA velocity. Over time, PSA values should stay about the same or may slightly creep up. Therefore, when a PSA value increases significantly from one year to the next even if it is still below 4.0 ng/dl, it calls for further evaluation.  What is considered significant? This is still up for debate in scientific circles, but some research points to a year to year increase of 0.75 ng/dl as being quite significant.

 

TSH stands for Thyroid Stimulating Hormone.  A high TSH result often means an underactive thyroid gland (hypothyroidism) that is not responding adequately to the stimulation of TSH due to some type of acute or chronic thyroid dysfunction. Rarely, a high TSH result can indicate a problem with the pituitary gland, such as a tumor producing unregulated levels of TSH, in what is known as secondary hyperthyroidism. A high TSH value can also occur when patients with a known thyroid disorder (or those who have had their thyroid gland removed) are receiving too little thyroid hormone medication.  A low TSH result can indicate an overactive thyroid gland (hyperthyroidism) or excessive amounts of thyroid hormone medication in those who are being treated for an underactive (or removed) thyroid gland. Rarely, a low TSH result may indicate damage to the pituitary gland that prevents it from producing adequate amounts of TSH.

 

HbA1c stands for Hemoglobin A1c. The hemoglobin A1c test (also called H-b-A-one-c) is a simple blood test that shows the average amount of glucose (sugar) that has been in a person’s blood over the last 2-3 months. The hemoglobin A1c test shows if a person’s average blood glucose is close to normal or too high. It is the best test for a health care provider to tell if a person’s blood glucose is under appropriate control, whether you have diabe¬tes or are at risk for diabetes. Sugar in the bloodstream can become attached to the hemoglobin molecule, the part of the red blood cell that carries oxygen. This process is called glyco¬sylation. Once the sugar is attached, it stays there for the life of the red blood cell, which is about 120 days. The HbA1c test measures the amount of glu¬cose “sticking” to the hemoglobin in the red blood cells. Results are given in percentages (%). The HbA1c “big picture” complements the day to day “snapshots” obtained from the self-monitoring of blood glucose in individuals who are diabetic or who monitor their blood sugar with home testing. Everyone, regardless of whether they have diabe¬tes, has some glucose attached to their red blood cells. A person without diabetes would typically have an HbA1c level below 5.6%. Those at high risk for diabetes (or who are pre-diabetic) show lev¬els between 5.7 - 6.4%. A diagnosis of diabetes is confirmed with an HbA1c level above 6.5%. For an individual with diabetes, the treatment goal is to have an A1c level near or below 7%. An A1c result of 8% or higher is a sign that changes need to be made to better manage one’s glucose levels. It is critical that you share and review these results with your physician or medical care provider. Together, determine a strategy that is appropriate for you to maintain or improve these results, lowering your risk for diabetes and the complications which can arise from it.