Abstract
Clinical evidence of a thyroid disorder was present in 10 out of 40 patients with Addison's disease. Though the remaining 30 patients had no clinical evidence of thyroid disease, six (out of 15 tested) had thyroid microsomal antibodies and a considerably impaired response to thyrotrophin. These changes are interpreted as very early indications of developing thyroid failure. When circulating microsomal antibodies are found this seems to indicate the presence of established thyroid disease.