Explanation of Laboratory Tests

Glucose: Glucose is the body’s main source of fuel to use for growth and energy. The cells in our bodies cannot use this glucose without insulin, which is a hormone produced in the pancreas. People with diabetes usually do not produce enough insulin, so that glucose builds up in the body (hyperglycemia). Conversely, some people have low blood glucose levels (hypoglycemia). The blood glucose test is collected in a fasting state and will tell what your glucose level is at the time it is drawn. This test may help diagnose either hyper or hypoglycemia.  Blood Urea Nitrogen (BUN): Blood urea nitrogen is a waste product from protein breakdown in the liver. The kidneys excrete BUN, and when your kidneys are not functioning properly, the level of BUN in your blood will rise. Strenuous exercise, a high protein diet, blood loss, and dehydration can also cause a high BUN level. Creatinine: The concentration of creatinine in your blood depends on your kidney function and your individual muscle mass. High levels usually indicate depressed kidney function. Your physician should evaluate high values. Sodium and Potassium: These are electrolytes that function to control water and salt balance in your body. Low levels of sodium can be caused by heart or kidney failure, or sodium loss due to diarrhea or vomiting. High levels can be caused by excessive intake of salt or dehydration. Low levels of potassium may be found in persons taking water pills or in those not receiving enough dietary potassium. Low potassium may cause muscle weakness and heart problems. High levels may be found in kidney disease or overuse of potassium supplements, and may also result in heart problems. Values outside of the reference ranges provided indicate the necessity of evaluation by your physician. Chloride: Chloride is an electrolyte regulated by the kidneys, and is important to the function of nerves, cells, and muscles. Borderline high or low levels have little significance. Uric Acid: A high level of uric acid in your blood may cause kidney stones or gouty arthritis. Diet, alcohol, stress, or certain diuretics may cause a high level of uric acid. Your physician should evaluate high levels, while low levels are usually not considered significant. Calcium: Blood calcium tests 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 or ionized calcium is circulating in the blood. Low levels of calcium are related to malnutrition. High levels can be caused by bone disease, excessive use of antacids and milk, overdosing on Vitamin D and hyperparathyroidism. Your physician should evaluate excessively high calcium levels. Phosphorous: Phosphorous is important for muscle and nerve function. Low phosphorus levels are associated with malnutrition and can lead to muscle weakness. High levels can be found with kidney disease. Your physician should evaluate levels outside of the reference ranges.   Total Protein: Total protein measurements can reflect nutritional status, kidney disease, liver disease, and many other conditions. If total protein is abnormal, further tests may be performed to identify which protein fraction is abnormal, so that a specific diagnosis can be made. Albumin: About two-thirds of the total protein circulating in your blood is albumin. Low albumin levels are associated with malnutrition, too much water in the body, liver disease, kidney disease, severe injury, or major bone fractures. Total Bilirubin: When bilirubin levels are high, a condition called jaundice (a yellowing of the skin and the whites of the eyes) occurs, and further testing is needed to determine the cause. Too much bilirubin may mean that too many red cells are being destroyed, or that the liver is incapable of removing bilirubin from the blood, either because of liver disease or blocking of the bile ducts. SGOT/AST: This enzyme is mainly found in the heart, liver, and muscles. It is released into the blood when any of these organs are damaged. It is usually associated with liver or heart disease. SGPT/ALT: This enzyme is found mainly in the liver. Damage from alcohol, strenuous exercise, and many disease states can cause high values for both SGPT and SGOT. Your physician should evaluate high values. Low values are not considered significant.   Gamma-Glutamyl Transpeptidase (GGT): Gamma-glutamyl transpeptidase is an enzyme primarily found in the liver. Drinking too much alcohol, certain drugs, liver disease, stress, physical exertion, and bile duct disease can cause high GGT levels. Your physician should evaluate very high values. Low values are not considered significant. Alkaline Phosphatase (ALP): This enzyme is found in all areas of the body, but the most important sites are the bone, liver, bile ducts, and gut. A high level of ALP may indicate disease of the bone, liver, or bile ducts. Certain drugs may also cause increased levels. Growing children have much higher levels than adults. Low levels are not considered significant. Thyroid Stimulating Hormone (TSH): Thyroid stimulating hormone is the pituitary hormone which controls thyroid gland function. A TSH test is used to screen for and diagnose thyroid disorders and monitor treatment. Very high or low values should be evaluated by your physician. Iron: Iron is needed to help form adequate numbers of normal red blood cells, which carry oxygen throughout the body. Iron is a critical part of hemoglobin, the protein in red blood cells that binds oxygen in the lungs and releases it as blood travels to other parts of the body. Other cells also need iron, especially muscle (which contains another oxygen binding protein called myoglobin). Low iron levels can lead to anemia, in which the body does not have enough red blood cells. Other conditions can cause you to have too much iron in your blood. Cholesterol: Cholesterol is different from most tests in that it is not usually used to diagnose or monitor a disease but is used to estimate risk of developing heart disease. Because high blood cholesterol has been associated with hardening of the arteries and heart disease, cholesterol testing is considered a routine part of preventive health care. High results should be discussed with your physician. Triglycerides: Triglycerides are fatty substances in the body that are related to higher risk of heart disease. Triglycerides are recommended as routine tests to evaluate risk of heart disease in healthy adults. The test for triglycerides is not often ordered alone since risk of heart disease is multifactorial. However, if you have high triglycerides and are being treated, a triglyceride test may indicate treatment is working.   HDL-Cholesterol: HDL- (high density lipoprotein) cholesterol testing is used to determine your risk of heart disease. HDL is considered the "good" cholesterol, and if your cholesterol is high due to high HDL, you are probably at low risk for heart disease. This test is normally ordered as part of a lipid profile. It has been shown that the higher the level of HDL, the lower the risk of developing heart disease. LDL-Cholesterol: LDL- (low density lipoprotein) cholesterol is used to predict your risk of developing heart disease. Of the many forms of cholesterol in the blood, the LDL-cholesterol is considered the most important in determining risk of heart disease. Treatment decisions are based on LDL values. Elevated levels of LDL increase risk for heart disease. It has been shown that the lower the amount of LDL the lower the risk of heart disease. Cholesterol Risk Ratio: This ratio is obtained by comparing the total cholesterol level to the HDL-cholesterol level and factoring in the triglyceride level. The higher this ratio, the greater the risk of coronary heart disease.

Fast for 12 - 14 hours to achieve optimum results

Values which are outside of expected normal ranges:

• may indicate problems requiring further medical evaluation
• may be due to your non-fasting state
• may be due to the possibility of processing error
• may be due to normal variation

If you should compare your values with other persons, be aware the normal values are age and sex dependent. Consult your physician with further questions, and make an appointment for further evaluation if he/she deems it necessary. It is seldom possible to diagnose or treat a disease based on one blood test. However, it may help you to learn more about your body, detect a potential problem, and encourage you to change your personal habits to benefit your health.

Description of Chemistries

SODIUM (Na+) and CHLORIDE (Cl-): These are electrolytes that are regulated by the kidneys and the adrenal glands. They are important for the functioning of nerves, muscles and most cells. If one is outside the normal range, but not the other and the other results are normal, it is probably not significant. If both are outside, further evaluation should be done.

POTASSIUM (K+): This is one of the electrolytes that are very carefully controlled by the kidneys. It is important for the proper functioning of nerves and muscles, especially the heart. Any values outside of normal range, high or low, require medical evaluation. This is especially important if you are taking a diuretic (water pill) or heart medication (Digoxin, Lanoxin, etc.).

BLOOD UREA NITROGEN (BUN): This is a waste product produced in the liver and excreted by the kidneys. High values indicate poor kidney function. Also, high protein diet and/or strenuous exercise may cause an elevation. Low values may be seen during pregnancy.

CREATININE (CREA): This is also a waste product excreted by the kidneys. High protein diet does not affect creatinine. A physician should evaluate high values, especially if the BUN is elevated as well. Low values are not significant. Non-prescription drugs (aspirin, cold medications, vitamins, etc.), prescription drugs, and alcohol often affect your test results. Your health care provider must have a complete and honest picture to evaluate your results effectively. This information will save you both time and money.

GLUCOSE (GLUC): This is a measure of sugar levels in your blood. High values are associated with diabetes. Low values are present with hypoglycemia. Consult your physician if your value is over 200, even if you are a diabetic. If you did not fast, the value could be falsely elevated.

CALCIUM (CALC): This mineral is controlled by the kidneys and the parathyroid gland. It is found primarily in bone but is also important for proper blood clotting and nerve cell activity. Your physician should evaluate any elevated calcium.

BILIRUBIN (TBILI): Indicator of liver function. Abnormally high or low values may be significant in conjunction with other abnormalities.

ALKALINE PHOSPHATASE (ALKP): This is an enzyme found primarily in bones and the liver. Higher values are normal during growth as demonstrated in children and pregnant women. Abnormal elevation occurs due to liver or bone damage. Low values are not significant.

AST/SGOT: This is an enzyme that aids various chemical activities within the cells. Injury to these cells releases the enzyme into the blood. This enzyme is found in muscles, the liver and the heart. Damage due to a number of diseases, as well as alcohol and drugs, is reflected in high values which should be evaluated by a physician. Low values are not significant.

ALT/SGPT: Indicator of liver function.

TOTAL PROTEIN: Evaluate nutritional status; investigate edema.

ALBUMIN (ALB) and GLOBULIN (GLOB): These quantitate two types of protein in your blood. They are a general index of overall health. Globulin is the "antibody" protein important in fighting disease. If one of these is high but all other values are within normal range, the result is probably not significant.

CHOLESTEROL (CHOL): This is a substance found in the blood that is associated with heart disease. It is produced in the liver in sufficient quantities to meet the body's needs. Increased levels may be due to improper eating habits. Foods of animal origin (meat and dairy products) contain cholesterol and the body manufactures more cholesterol when the diet is high in fat, especially saturated fat.

TRIGLYCERIDES: This is a type of fat in the blood. Elevation tends to be glucose induced which makes fasting very necessary before testing. Elevated values may be seen in diabetes or heart disease. Decreased values are insignificant.

HIGH DENSITY LIPOPROTEIN (HDL): This is the lipoprotein that carries a lesser amount of cholesterol in its "package" and is sometimes called the "good" cholesterol. Elevation decreases the chance of heart disease and may be increased by regular exercise, losing weight, and refraining from smoking. Low levels increase the risk of heart attack.

LOW DENSITY LIPOPROTEIN (LDL): This is one of the blood lipoproteins that carry a portion of the cholesterol. These "packages of fat" contain the greatest amount of cholesterol and are sometimes called the "bad" cholesterol when elevated.

CHOLESTEROL - HDL RATIO (C/H): This is a calculation of the cholesterol level divided by the HDL level. This is sometimes called the Risk Ratio. The higher the ratio the greater the risk. The values vary for men and women. The following chart demonstrates these ratios.

CARDIAC RISK RATIO/MEN RATIO/WOMEN
Lowest Less than 3.8 Less than 2.9
Low 3.9 - 4.7 3.0 - 3.6
Moderate 4.8 - 5.9 3.7 - 4.6
High 6.0 - 6.9 4.7 - 5.6
Highest Greater than 7.0 Greater than 5.7

WHITE BLOOD COUNT (WBC): A count of the infection-fighting cells in your body. High counts often indicate an infection, while low counts may indicate a weakened immune system.

RED BLOOD COUNT (RBC) - HEMOGLOBIN (HGB) - HEMATOCRIT (HCT): All relate to the blood's ability to carry oxygen throughout the body. Low values indicate some level of anemia.

HEMOGLOBIN: Evaluate anemia, blood loss, hemolysis, polycythemia, and response to treatment.

HEMATOCRIT: Evaluate anemia, blood loss, hemolytic anemia, polycythemia, and state of hydration.

PLATELET COUNT: Evaluate, diagnose and/or follow up bleeding disorders.

MEAN CELL VOLUME (MCV): A measurement of Red Blood Cell size. High or low values may indicate a nutritional deficit.

MEAN CELL HEMOGLOBIN (MCH) - MEAN CELL HGB CONCENTRATION (MCHC): Measurements of the average hemoglobin contents of the RBCs. Significance of abnormal values depends on correlation with other measurements.

PROSTATE SPECIFIC ANTIGEN (PSA): This is a protein produced by the prostate gland. The measurement of PSA in the blood, when used in conjunction with digital rectal exam, is a useful screen for prostate cancer. Increased levels may also occur with advancing age, infection, and benign prostatic hypertrophy.

THYROID-STIMULATING HORMONE (TSH): The TSH test is often the test of choice for evaluating thyroid function and/or symptoms of hyper- or hypothyroidism. It is frequently ordered along with or preceding a T4 test. Other thyroid tests that may be ordered along with it or following an abnormal TSH result include a T3 test and thyroid antibodies (if autoimmune-related thyroid disease is suspected).
TSH testing is used to: diagnose a thyroid disorder in a person with symptoms, screen newborns for an under-active thyroid, monitor thyroid replacement therapy in people with hypothyroidism, diagnose and monitor female infertility problems, help evaluate the function of the pituitary gland (occasionally), and screen adults for thyroid disorders as recommended by some organizations, such as the American Thyroid Association.

A Healthy Thyroid:
Keeps your metabolism running smoothly

The thyroid gland produces a hormone, thyroxin, that helps regulate your metabolism. Metabolism is the process that turns food into energy, produces body heat and helps keep your body functions running smoothly. Your physician may order a thyroid test if he suspects you are having a thyroid problem, such as hypothyroidism or hyperthyroidism.

Hypothyroidism: occurs when the thyroid doesn't produce enough thyroxin. Your doctor may suspect this if you are experiencing symptoms such as abnormal drowsiness, weight gain, aching muscles, constipation, and dry skin.

Hyperthyroidism; occurs when the thyroid produces too much thyroxin. Your doctor may suspect this if you are experiencing symptoms such as weight loss, increased appetite, excessive sweating, heart palpitations, or vision trouble.

A simple blood test can help your doctor determine whether you have a thyroid problem and need treatment.

Information About

Blood chemistry testing

Now, more than ever, Americans are aware that good health is largely determined by habits and lifestyle. Most health professionals agree that eating right, not smoking, and getting regular checkups help a person maintain good health.

Regular physical exams can help your doctor detect problems while they are still easily treatable. One way your physician may check for disease is by ordering blood chemistry tests that provide information about the liver, kidneys, heart, lungs, bones, and metabolism by measuring:

Albumin, globulin, A/G ratio, total protein: To check for normal liver and kidney function.

Bilirubin: To determine if the liver is eliminating waste products and old red blood cells normally.

Enzymes: To check for normal levels, which indicate healthy body tissues.

Calcium, phosphorous: To check for healthy bones, kidneys, and parathyroid glands.

Blood urea nitrogen, creatinine: To detect kidney problems.

Uric acid: To detect gout.

Glucose: To screen for a diabetic or prediabetic condition.

Cholesterol, triglycerides: To determine the degree of risk for coronary heart disease.

Electrolytes: Important in maintaining normal cell function.

Your Healthy Heart
What your cholesterol level means

CHD is a narrowing and blockage of the blood vessels that supply blood to the heart. Because CHD is often without symptoms, your doctor may order a cholesterol test to detect potential problems early. Physicians often order the following four tests to assess a patient's risk of developing CHD.

Total cholesterol: The likelihood that a person will develop CHD is directly related to the amount of cholesterol in the blood. The higher level of blood cholesterol, the higher the risk of CHD.

HDL cholesterol: HDL is considered the "good" cholesterol. High levels of HDL protect against CHD.

LDL cholesterol: High levels of LDL are a risk factor for CHD.

Triglycerides: High levels of this fatty substance in the blood, especially when combined with high total cholesterol levels, are a risk factor for CHD. Elevated triglycerides are often found in patients with diabetes.

The results of these tests will help your doctor assess your risk of developing CHD. Of course, prevention is often the best cure. To help maintain good health, most health professionals recommend that you see your physician regularly, eat right, and don't smoke. 

It's true, there are some risk factors for coronary heart disease (CHD) that can't be controlled, such as age, sex, and family history. But, the good news is that you can control the three major risk factors for CHD: high blood pressure, and smoking. In fact, the death rate for CHD, the nation's leading killer, has dropped by an amazing 40 percent over the last 30 years. This is largely because patients are adopting healthy lifestyles and following their doctor's advice.

Protect against CHD.