Endocrine Diseases (General)

Endocrine diseases are those that affect the human endocrine system which are the group of ductless glands used to regulate the human body processes by secreting chemical substances called hormones, which are then carried to a number of specific target organs and tissues by the bloodstream. The diseases or disorders result in too much hormone secretion or too little hormones being secreted, or from problems within the body which prevent the hormone to be used effectively.

From the early 20th century, medical researchers have been involved in cataloging the various endocrine diseases and other disorders of the endocrine system. The first of these was disorders of the adrenal system. These include problems with adrenal insufficiency such as Addison's disease, congenital adrenal hyperplasia (sometimes called adrenogenital syndrome), and mineralocorticoid deficiency. Other adrenal problems include Conn's syndrome, Cush-ing's syndrome, pheochromocytoma, and adrenalcortical carcinoma.

Another range of problems with the endocrine system can be categorized as glucose homeostasis disorders, such as diabetes mellitus, and hypoglycemia, which include idiopathic hypoglycemia and insulin-oma. Metabolic bone diseases include osteoporosis, osteitis deformans (sometimes called Paget's disease of bone), and rickets and osteomalacia.

There were also a large number of pituitary gland disorders such as diabetes insipidus, hypopituitarism (and panhypopituitarism), and pituitary tumors. The last includes pituitary adenomas, prolactinoma (and hyperprolactinoma), acromegaly, and Cushing's disease. Other disorders include those affecting the parathyroid gland and the thyroid gland: hyperparathyroidism, pseudohyperparathyroidism primary hyperparathyroidism, secondary hyperparathyroidism, and tertiary hyperparathyroidism—some connected with Graves-Bassedow disease.

The other endocrine diseases involve sex hormones, including disorders of sexual development, and intersex disorders, such as hermaphroditism, gonadal dysgensis, and androgen insensitivity syndromes; hypogonadism such as gonadotropin deficiency, Kallman syndrome, Klinefelter syndrome, ovarian failure, testicular failure, and Turner syndrome.

The earliest evidence of medical practitioners becoming aware of the endocrine system was the Chinese, who, as early as 3000 b.c.e. started diagnosing some endocrinologic disorders and working out some effective treatments. One of the most obvious of these disorders was goiter which involved an enlargement of the thyroid gland, which rapidly becomes noticeable on sufferers. It was discovered that eating seaweed could help reduce the problem, but it was not until the 19th century that it was found that the cause was iodine deficiency and the cure was effective as seaweed was rich in iodine.

The creation of eunuchs in the ancient world in Egypt, China, and elsewhere led to direct endocrinologic intervention, although this was not realized at the time. In Europe from the Middle Ages until as late as the 18th century, some boys were castrated to preserve their treble voices for singing in cathedral choirs. It was, curiously, the system of castration that led to some early surgeons to begin to study the endocrine system, even though it did not have that name at the time. A Scottish surgeon and anatomist, John Hunter, practicing in London, managed to successfully transplant the testis (testicle) of a rooster into the abdomen of a hen.

His work was followed by that of French physiologist and neurologist Charles-édouard Brown-Séquard, who concluded that he believed the testicles contained a substance that had rejuvenation properties. In 1889, he injected himself with fluid from the testicles of freshly killed dogs and guinea pigs, to which he had added water. His work helped pioneer the studies of endocrinology, and hence helped others start work on describing, then diagnosing endocrine diseases. The work of the French physiologist Claude Bernard came up with the concept of humans—and, indeed, other living organisms—having what he described as the milieu intérieur (internal environment). This led to Walter Bradford Cannon, the American physiologist, using the homeostasis for the first time.

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