Medical history is built on traditions from the Middle East (Egyptian, Jewish, Arabian), the Far East (mostly Chinese), and Europe, with Greek, Roman, medieval, and modern elements. Because of geographical distances, language or religious communication barriers, or rejection of older traditions, the European medical community had to rediscover facts which were known in ancient Egypt, China, or Arabia a long time ago. Whether an endocrinological profession was known in ancient times may be doubted.

Below, we will separate ancient times, the new age, and modern times without any assessment in mind. The search for disease causes by scientific means—hypothesizing, performing experiments, refuting or corroborating the hypothesis—was established by the Greeks.

Table 2.1 does not cover the richness of modern discoveries for lack of space. Therefore, we conclude the historical overview with the reevaluation of the hypothalamic–pituitary portal system.