Exercise and the cardiorespiratory system of thyrotoxicosis.

Dyspnoea is a common, if not the commonest symptom, of thyrotoxicosis (Wayne) and cardiovascular overactivity is recognized as a cardinal sign of the disease. Despite the prominence of these manifestations the underlying physiology is poorly understood. Probably the major reason for this is lack of data. Stein, et al.,(l961) have recorded a relatively comprehensive study of pulmonary function on thirteen patients at rest and on exercise. Their findings are discussed later but they, in common with all other investigators, did not report on the exercise diffusing capacity