Testing your older patient's thyroid function.

Thyroid disease cannot be diagnosed through any single test. Normal aging does affect the values of some test parameters in the elderly. When interpreting laboratory test results in the elderly, careful consideration should be given to gender, concurrent acute or chronic illness, nutritional and mental status, as well as possible recent administration of iodinated radiocontrast media and drug therapy. When these factors have been excluded and preliminary routine thyroid function are abnormal or marginally suspect, the usual standards for younger adults, slightly modified, should suffice for diagnosing both hypo-and hyperthyroidism. Patients with complications may require special measurements of serum FT4 and FT3 levels as well as the TSH and T3 response to TRH. These tests will provide additional supportive diagnostic assistance.