Since the hormones of the thyroid gland, i.e. T 4 and T 3 are increased in the blood, a blood analysis of the patient for estimation of these hormones, will make clear the diagnosis. However, for a screening programme for detecting the occult/ hidden cases of hyperthyroidism, estimation of the serum free T4 ideal, since T4 is the major hormone of the thyroid.
All thyroid function tests, like T4 and T3 must be interpreted with care. The levels of various thyroid function tests may be altereci in patients who are on drugs like salicylates, propranolol (one of the antihypertensive drugs), glucocorticoids.
Other conditions in which thyroid function tests may be changed are in the case of patients who are taking nonsteroidal anti-inflammatory drugs. Or, in whom contrast media have been used for imaging studies, or in the cases of severe/ recurrent vomiting during the period of pregnancy, although in such conditions, the effect is only transitory.
Further, in cases which are acutely serious, as a result of some disease, or in the case of patients who are suffering from severe mental/psychiatric disorders, thyroid function tests have to be read with caution.
Treatment of a hyperactive thyroid gland
Overactivity of the thyroid gland as a result of Graves’ disease can be successfully brought down to normal levels by the use of various antithyroid drugs, and the one commonly used is neomercazole (carbimazole). While on antithyroid therapy, one has to regularly watch the activity of the thyroid gland, because it is a disease in which both natural remissions and relapses may occur from time to time. Hence, such patients will need lifelong care.
After initial therapy, the patient may be put on a maintenance dose of antithyroid drugs. As the drug shows its effect, T4 and T3 will return to the normal level, and the size of the thyroid gland may also decrease. However, at any time, thyroid activity may become low (hypothyroidism), even when the patient is on a maintenance dose of the antithyroid drug, as he may get natural remission. Therefore, T4 and T3 may have to be repeated frequently, when the clinical picture so warrants.
Further, the patient may even get a natural relapse of overactivity of the thyroid gland, while still on the maintenance dose of antithyroid drugs, and in such cases T3 (rather early) and T4 will rise, and will give the true status of the thyroid gland. Hence it is clear that thyroid function tests must be carried out from time to time so that the function of the thyroid gland is perfectly maintained, and the patient lives a normal, satisfactory life.
Radio-iodine or even surgery may be considered necessary in some of the cases.
In the case of solitary nodule/s responsible for the overactivity of the thyroid gland, after controlling the elevated activity of the gland with an antithyroid drug, these may be removed surgically for a lasting cure of the disease.
Prophylaxis for thyroid cancer:
Even if the tests do not prove malignancy in thyroid nodule/ s, still such nodule/ s must be removed surgically as a preventive measure against cancer. These nodule/s may be responsible for the hyperactivity of the thyroid gland, and hence their removal is a must. Once removed; all such nodule/s must be subjected to histopathology which may prove very helpful in establishing the diagnosis.