RESUMO
This study shows that serum thyroxine radioimmunoassay measurement is the best single initial test and inexpensive method for the diagnosis of functional disorders of thyroid gland, particularly in those clinically euthyroid patients. Undoubtly, a single test instead of two or more would require less time and personnel needed to screen a large number of patients. The clinician will then determine whether further thyroid function tests are needed. This approach will avoid the improper use of several tests and waste of valuable resources. The normal range of serum [[T4]] quoted by the company does not necessarily apply to our community, and it should be probably increased to enhance the specificity of the test. A study to determine the final normal ranges of serum thyroid hormones in our community is already going on by our colleagues in Al-rasheed Military Hospital