you ever wonder what your doctor is checking for when he or she does
your blood work? Most people know about cholesterol, but how about the
BUN? I will attempt to explain the meaning of the blood work results.
glucose (blood sugar) is a test for diabetes. Normal values are
below 100. Diabetes is defined as a fasting blood sugar of greater
than 126 on two separate occasions. Frequently it will be on the low
side, but this is rarely of any significance. The value for the blood
sugar will decrease if the test is not performed shortly after it is
drawn. If it is very low, you may want to go by your doctor's office
and get a finger stick for the blood sugar level, so that it can be
potassium, and magnesium are called electrolytes, and they
will sometimes become significantly abnormal with certain medications
or different forms of lung, heart, or kidney disease. They are not
related to the amount of salt you have in your diet. Water pills are
most frequently implicated when the potassium is low. Some
antidepressants and water pills can cause the sodium and chloride to
Calcium and phosphorus
are minerals in your bones, and they may be abnormal with certain
hormonal diseases, or may be related to tumours in your bones.
Phosphorous is difficult to test and is frequently out of the normal
range. It is rarely a significant abnormality, but your physician can
decide whether or not to pursue a mildly abnormal result.
albumin, A/G ratio and globulin results of your blood work are a
measure of the liver function and will be abnormal with liver damage
as seen in cirrhosis of the liver. The alkaline phosphatase,
lactate dehydrogenase, gamma-glutamyl transferase, SGOT, and SGPT
results are a measure of on going liver damage. Liver damage could be
seen as a reaction to numerous medications, alcohol toxicity,
hepatitis, tumours in the liver, or a number of viral illnesses.
Frequently, one or two of these tests may be only slightly elevated
which is not always significant, but may have to be repeated at a
later date, after stopping medicines or avoiding alcoholic beverages.
creatinine, and BUN/creatinine ratio are a very accurate
measure of kidney function. The creatinine will be elevated with
significant renal disease. A low serum creatinine or BUN is not
usually a sign of disease.
Uric acid is
a chemical in the body that may cause gout if it becomes elevated.
Gout is a hereditary form of arthritis. A low uric acid is rarely a
sign of disease.
binding capacity, and % saturation measure the amount of
iron you have in your body. Results may be low because of poor dietary
intake of iron, or from loss of blood from the body. A low serum iron
is frequently seen in women that have heavy periods and have a diet
low in iron. Bleeding from the gastrointestinal tract can also result
in a low serum iron. This bleeding may be visible blood loss, or it
may be occult, which means it is not readily apparent to the naked
eye. It is important to check for blood in the stool if your iron is
low. Occult blood in the stool can be tested with Hemocult slides
The desired level of
total cholesterol is under 200. It is important to measure the HDL-cholesterol
and the LDL-cholesterol. The HDL- cholesterol is the
good cholesterol, and it is okay for it to be high. It seems to
protect the heart and blood vessels from becoming clogged. One way to
estimate your risk of having heart disease, is to divide the total
cholesterol by the HDL-cholesterol. This ratio, ideally,
should be less than 3.5, which would be associated with only one-half
the risk of an average person having a heart attack. Your ratio can be
improved by increasing the HDL-cholesterol, or decreasing the total
cholesterol. This can usually be accomplished by regular aerobic
exercise, such as walking, running, swimming, aerobic classes, or any
exercise that maintains your heart rate at a fairly high level. You
should attempt to maintain your heart rate at 70% or greater of your
maximal predicted heart rate. Your predicted maximal heart rate is
estimated by subtracting your age from 220. If you are 40 years old,
your predicted maximal heart rate is 220-40=180. Therefore, 70% of
this would be 126. You should try to SLOWLY get to the point where you
can exercise for 30-60 minutes a day, keeping your heart rate above
125 beats per minute. Ideally, this should be done daily.
level is determined by heredity, exercise, and diet. Unfortunately,
heredity can be a very powerful influence on both the total
cholesterol, LDL-cholesterol and the HDL-cholesterol level.
Diet alone has minimal effect on cholesterol. Exercise has some effect
particularly on increasing the HDL and lowering the total cholesterol
and LDL-cholesterol. Diet and exercise together are the best
non-medicinal treatment. Medications called statins have been a major
advance in the treatment of high cholesterol. The LDL-cholesterol is
used to decide whether or not someone should take a statin. It should
be less than 130 in healthy individuals and less than 70 in
individuals with diabetes or heart disease. Examples of statins are
Mevacor, Lipitor, Pravochol and Crestor. Mevacor is presently the only
generic statin. It works very well and is usually well tolerated.
It is important to
realize that the cholesterol level may vary somewhat from day to day,
and if you have an abnormal reading, it may need to be checked on
several occasions to really get a good feel for its true value.
are another fat in your blood that are not quite as important as the
cholesterol in the development of heart disease. The amount of this
fat in your blood is influenced by your diet, and if it is elevated,
you may need to get the test repeated when you are fasting. Eating
within 14 hours of the blood test, may make the triglycerides
blood count (CBC) checks your white blood cells (WBCs) as
well as your red blood cells. The red blood cells,
hemoglobin, hematocrit, mcv, mch, mchc and rdw all are
checks for different kinds of anemia.
Anemia is when your
hemoglobin level is low, and you may manifest symptoms such as
fatigue, headaches, and weakness.
Your WBCs are
responsible for fighting off infection. They may decrease if you have
certain viral infections, but they increase with most bacterial
involved in making your blood clot; occasionally, they will decrease
to very low levels with certain viral infections. The Neutrophils,
lymphocytes, monocytes, eosinophils, and basophils are
specific types of WBCs, that are counted by hand as well as by
the machine performing CBCs. The percentages of different types
of WBCs will vary with many factors, such as viral infections, age,
and even recent exercise. If you have allergies, the eosinophil count
will frequently be elevated.
The TSH (thyroid
stimulating hormone) is a hormone that is a very sensitive measure
of your thyroid function. The thyroid gland is in the neck and
produces a hormone called thyroxine, that is responsible for your
metabolism. An under active thyroid will cause fatigue, constipation
and depression, along with numerous other symptoms. An overactive
thyroid will cause anxiety, weight loss, diarrhea, and many other
symptoms. The TSH level is inversely related to your thyroid gland
output of hormone. The brain monitors the thyroid hormone in the
blood, and sends out more TSH when the thyroid hormone level gets low,
stimulating the thyroid gland to produce more thyroid hormone.
However, if the thyroid hormone level is high in the blood, the brain
senses this and decreases the production of TSH. This is a signal for
the thyroid gland to decrease the production of thyroid hormone.
stands for prostate specific antigen that is a screening test
for cancer of the prostate gland. The American Cancer Society
recommends that men over the age of 50 have a yearly PSA test. Men
over the age of 40 should have a yearly PSA if they have a family
history of prostate cancer, or if they are African-American.
stimulating hormone) is a hormone secreted by a part of the brain
known as the pituitary gland. It is frequently ordered in
females to see if they are going through menopause. It will
become elevated when menopause begins.
Many people will
have one or more of the test results in the abnormal column. This is
usually not significant, but should be discussed with the doctor.
is a test for evidence of a urinary tract infection, diabetes, kidney
disease, or liver disease.
Other tests that may
or may not have been performed, depending on your age and sex, are the
EKG and PAP smear. The PAP smear will check for
cancer of the cervix. The EKG will check for evidence of heart
disease. If you were given Hemocult slides, be sure to complete
them and send them back to the lab to check for cancer of the colon.
It has been proven that you will reduce your chance of dying of colon
cancer by 30% if you perform this simple test every year. Just try to
do the best you can with the dietary restrictions. The only factor
that is particularly important is to adhere to the recommendation of
not taking over 250 mg of vitamin C for three days before completing
information provided above is offered as a community service about
health-care issues and is not a substitute for individual
consultation. Advice on individual problems should be obtained from
your personal physician.