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Explanation of Blood Tests
PLEASE NOTE: In keeping with our patient confidentiality standards, results
of blood screenings performed by Cass County Memorial Hospital are
provided only to you, the patient. We do not send the test results to your
doctor. We encourage you to share this important health information with
your primary care provider.
This information is provided to help you understand your blood tests.
Abnormal results may be the result of several factors and do not always indicate the presence of any
disease. Some of these factors are: a) You ate too soon before your blood was drawn; b) Medications
you are taking (if any) are interfering with the blood tests; c) when many analyses are performed, a few
may fall outside the normal range and simply need to be repeated. In some instances, abnormal test
results do indicate that a medical evaluation is needed.
It is not possible to diagnose or treat any disease or problem with these blood tests alone. The tests can
help you learn more about your body and help detect potential problems in the early stages when
treatment or changes in your habits can be most effective.
Non-prescription drugs (aspirin, cold medication, vitamins), prescription drugs, and alcohol intake often
affect blood test results. Your doctor must have a complete and honest picture of your use of
medications in order to effectively interpret the results of your blood tests.
GLUCOSE is a measure of sugar levels in the blood. High values are associated with eating too soon
before the test, or with diabetes. If you have not had diabetes, consult your physician if your sugar level
is over 120 (fasting). If you do have diabetes, consult your physician if your sugar level is over 160
(fasting).
SODIUM is regulated by the kidneys and adrenal glands. It is important for the functioning of nerves,
muscles and most cells. Low levels may be caused by diuretics, or kidney/adrenal diseases.
POTASSIUM is controlled very carefully by the kidneys. It is important for the proper functioning of
nerves and muscles, particularly the heart. Values outside the expected ranges, high or low, generally
require medical evaluation. This is especially important if you are taking a diuretic (water pill) or heart
pill (digitalis, Lanoxin).
CHLORIDE is a blood molecule whose actions are related to sodium, potassium and carbon dioxide.
CO2 (Carbon Dioxide) is a molecule found in blood. Its levels may be high in certain respiratory
problems or low in conditions such as diabetes.
BUN/CREATININE are wastes excreted by the kidneys. They are very good indicators of kidney
function. High values require medical evaluation. Low values. are probably not significant.
AST/ALT/GGT are abbreviations for proteins called enzymes which help control chemical activities
within cells. They are found in muscle cells, liver cells, and heart muscle cells. Any injuries to
these cells cause the release of the enzyme into the blood. Damage from alcohol and a number of
diseases causes high values and should be evaluated by your doctor.

TSH measures one of the thyroid hormones. This test is useful in diagnosing thyroid disease and
monitoring patients on thyroid replacement therapy.
BLOOD FATS
▸ CHOLESTEROL is produced by the liver and also acquired through the diet. High levels of this
fatty, wax-like substance in the blood may clog arteries, causing heart attack or stroke. ➾ HDL (High Density Cholesterol Carrier) is also known as "good" cholesterol. It is produced
in the liver and released into the bloodstream where it carries LDL from the artery walls back to the liver for breakdown and release from the body. LDL (Low Density Cholesterol Carrier) is also known as "bad” cholesterol. It is the
substance that sticks to the artery walls causing atherosclerosis. Cigarette smoking, overweight, and physical inactivity increase the LDL. HDL RATIO is a ratio of HDL and total cholesterol and is an assessment of heart disease
risk.

▸ TRIGLYCERIDES are another form of fat in the blood. High levels are caused by heredity,
diabetes, or alcoholism. Triglycerides are a factor in heart disease risk.
BLOOD CELL MEASUREMENTS
▸ WHITE BLOOD COUNT is involved with the body's infection response and immune processes.
Elevated values may indicate the body is fighting a bacterial infection or has a blood disorder. Stress may also elevate the WBC. Low values are sometimes an indication of a viral infection, associated with certain medications or indicate a bone marrow problem.
▸ RED BLOOD COUNT is the measurement of the cells that carry oxygen to all body tissues and
give blood its red color. Low values may indicate anemia and reduced oxygen to the tissues.
▸ HEMOGLOBIN is the substance which combines with oxygen in the red cells, carrying it to the
tissues. Iron is needed to manufacture hemoglobin. Low values may indicate anemia and low levels of iron. Extremely high values are associated with some unusual blood disorders.
▸ HEMATOCRIT is a measure of the percent of red blood cells in the blood. Values rise and fall
with the red blood count and hemoglobin values.
▸ MEAN CELL VOLUME is a calculation related to red blood cell volume and hemoglobin
concentration. Abnormal values are found in various types of anemia.

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