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.
| Goiter refers to enlargement of your thyroid gland.