Endocrinology is a field in biology and medicine that deals with the endocrine system. The organs involved in the endocrine system include the pituitary, thyroid, adrenals, ovaries, testes and pancreas.

These glands release hormones into the blood. Hormones of the endocrine system perform a variety of functions, and some hormones may have varying effects depending on which organ is targeted. Organs may be targeted by several different hormones.