The endocrine system consists of glands that secrete hormones directly into the blood. Hormones have many different functions and modes of action; one hormone may have several effects on different target organs, and, conversely, one target organ may be affected by more than one hormone.
The clinical specialty of endocrinology focuses primarily on the endocrine organs, meaning the organs whose primary function is hormone secretion.
These organs include the pituitary, thyroid, adrenals, ovaries, testes, and pancreas.
An endocrinologist is a physician who specializes in treating disorders of the endocrine system, such as diabetes, hyperthyroidism, and many others