The methods of clinical diagnosis have become increasingly complicated and specialised. This should lead to a better understanding of pathological processes. At the same time economic reasons make it imperative to weed out those methods, which have become obsolete. The present trend to adopt any new methods and at the same time continue conservatively with the old ones must be checked.
Endocrinology gives us some very good examples of this tendency. Thyroid disease may be regarded as a striking instance. From simple inspection and palpation of an enlarged gland purely clinical observation proceeded towards the recognition of Graves' disease, simple goiter and hypothyroidism as clinical entities. By the use of blood cholesterol values and determinations of the patient's basal metabolism as indirect evidence of thyroid function, we have now reached the stage when protein-bound iodine in the blood can be measured, and the uptake and retention of labelled iodine in