Simply put, endocrinology is the study of endocrine glands. Endocrine glands are a group of glands in the body which secrete hormones. The purpose of the secreted hormones is to evoke a specific response in other cells of the body which are located far away. The hormones are secreted into the blood stream giving them access to all other cells of the body. Endocrine systems include, but are not limited to: thyroid, parathyroid, adrenal, pancreas, pituitary and the hormones these glands produce.
Many disease states are associated with malfunctioning of the endocrine systems.