Thyroid disorders. The general internist's approach.

A variety of thyroid abnormalities are commonly seen in clinical practice and can in many cases be accurately diagnosed and managed by the primary care physician. In patients with hypothyroidism and hyperthyroidism, classic features are usually present, but in some, particularly the elderly, the conditions present atypically. In addition, several other conditions can mimic thyroid problems, and a number of drugs can alter thyroxine levels or actual thyroid function. Laboratory measurements, including serum thyrotropin and thyroxine levels and triiodothyronine uptake, may be helpful in diagnosis. Drug therapy is indicated in most cases, and surgery is necessary in some. Thyroiditis can be of the subacute or chronic type. Aspirin, propranolol (Inderal), and occasionally glucocorticoids are used in the former. Therapy in the latter depends on results of thyroid function tests. In cases involving thyroid nodules, radioactive iodine screening and fine-needle aspiration are useful diagnostically. In patients with possible malignancy, surgery is indicated. Patients who have benign lesions are treated with thyroid hormone-suppressive therapy.