Endocrinology is the branch of medicine that deals with the synthesis, secretion and action of hormones from a network of glands in the body. The hormones coordinate the functioning of different cells, tissues, and organs in the body through feedback mechanisms. Diseases of the endocrine system occur when there is a fault in either the synthesis, secretion or release of these hormones. It is important for a medical student to be well acquainted with these diseases primarily because the endocrine system practically controls the functioning of the entire body and also because the manifestations of these diseases are often non specific, as well as long lasting.