Anemia
Anemia is a disorder characterized by a decrease in the number
of red blood cells that carry oxygen to various body tissues. If
you have hypothyroidism, you may also have an associated mild anemia
as one manifestation of the general slowing of your body functions
that occurs in your condition. The anemia usually causes no symptoms
and corrects itself when your hypothyroidism is treated. It is not
a separate disease, but is due instead to the low thyroid hormone
level.
A more serious type of anemia, known as pernicious anemia, is a
separate disease that tends to occur in older patients who have
or have had Graves' disease or Hashimoto's thyroiditis, and their
relatives. This kind of anemia is caused by a deficiency of Vitamin
B12.
Under normal circumstances, cells lining your stomach make a substance
known as intrinsic factor that enables your body to absorb Vitamin
B12 from food. Some individuals lose the ability to absorb Vitamin
B12 due to failure of the cells that make intrinsic factor. The
damage seems to be caused by a self-destructive process involving
the body's immune system, similar to what occurs in Addison's and
Hashimoto's diseases.
Vitamin B12 is an important ingredient in the manufacturing of
red blood cells, and if levels of this vitamin fall, anemia may
result. Vitamin B12 is also important in nourishing your nervous
system, so if you develop pernicious anemia, you also may experience
numbness and tingling of your hands and feet, loss of balance, and
even leg weakness. It is not clear how many patients who have thyroid
functional problems also develop pernicious anemia. Some studies
have suggested that as many as 5 percent of patients with Graves'
disease and 10 percent of those who have Hashimoto's disease may
develop this condition.
Since pernicious anemia tends to develop in later years, it is
probably even more common in older patients with either condition.
Therefore, it seems appropriate to measure the blood level of Vitamin
B in every patient over the age of sixty who has ever had Graves'
disease or Hashimoto's thyroiditis. Doctors do this because pernicious
anemia is both common and treatable. If your blood level of Vitamin
B12 appears low or borderline low, another test, known as a Schilling
test, can be performed. This test demonstrates whether you have
difficulty absorbing Vitamin Bl2 from your food. If you do have
pernicious anemia, it can be easily treated.
On the basis of new research, your physician may choose to treat
you initially with tablets of B12 to see if you are able to absorb
enough of the vitamin to restore your blood level to normal and
thus cure the condition. However, since your body's ability to absorb
B12 tends to decrease with time, you will probably need treatment
with a monthly intramuscular injection of Vitamin B12 as you grow
older.
Platelet disorders are also more common in this group of thyroid
patients than they are in the general population. Normally you have
about 2.5 million platelets in every teaspoonful of your blood.
Despite their small size, they play a major role in helping your
blood to clot normally. Some thyroid patients experience easy bruising
due to a decrease in the number or function of their platelets.
The bruising can become much worse if you take aspirin, or one of
the non-steroidal anti-inflammatory drugs such as ibuprofen (Advil
or Motrin) or Naprosyn. If that is your situation, your physician
may choose to order a platelet count or check your platelet function
with a "bleeding time" test, which tells how long it takes
your blood to clot. He or she may also recommend that you take an
alternative pain medication such as acetaminophen (Tylenol) which
will not worsen your bleeding tendency.
Very rarely, immune processes may destroy large numbers of platelets
producing thrombocytopenic purpura. The word purpura refers to red
or blue bruises which appear on the skin in this condition, especially
on the legs. Tiny purplish-red spots known as petechiae that represent
smaller areas of bleeding within the skin are also commonly present
in this condition. If you develop this type of rash, your physician
is likely consider it an emergency and order an immediate platelet
count because of the risk of more serious bleeding elsewhere. If
thrombocytopenic purpura proves to be your problem, treatment is
usually helpful, and often includes steroid medication.
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