The Interpretation of Thyroid Function Tests in Hospitalized Patients

NUMEROUS studies have demonstrated a high incidence of unsuspected hyperthyroidism and hypothyroidism in hospitalized patients.1,2In general, thyroid dysfunction is present in 2% to 5% of short-term hospitalized subjects and patients in long— term medical or psychiatric nursing facilities. Increased awareness of this high incidence, coupled with the problem that the clinical diagnosis of thyroid dysfunction in patients with other concomitant diseases, has resulted in an increase in screening for thyroid disorders. This increase in the ordering of thyroid function tests has led to the discovery that many hospitalized patients have abnormal findings on thyroid function tests that are unrelated to underlying thyroid disorders. The purpose of this review is to describe the multiple syndromes of altered thyroid function that have been reported in hospitalized patients and to develop a simple, cost-effective approach to thyroid function screening in these patients. Low Triiodothyronine Level and Low Thyroxine Level Syndromes: The