Hyperthyroidism in juvenile diabetes mellitus.

Three cases of hyperthyroidism occurring in juvenile patients with diabetes mellitus are presented. The presence of hyperthyroidism should be suspected in patients with diabetes mellitus when goiters develop and when there is unexplained weight loss, tachycardia, tremors, unexplained increases in insulin requirement, or instability of the diabetes with a tendency toward development of ketosis and/or ketoacidosis.