The endocrine system consists of 6 distinct organs: pituitary, adrenals, thyroid, parathyroids, gonads, and pancreatic islets. The last one is included in neuroendocrine system also. A basic feature of all endocrine glands is the existence of both negative and positive feedback control system that stimulates or regulates hormone production in a way that levels remain within the normal range. The pituitary gland is situated at the base of the brain in a hollow called sella turcica formed out of the sphenoid bone. Lesions of posterior pituitary and hypothalamus are uncommon. Two of the syndromes associated with hyperfunction of the posterior pituitary and hypothalamus are: inappropriate release of ADH and precocious puberty. Adenohypophyseal hypofunction is invariably due to destruction of the anterior lobe of more than 75% because the anterior pituitary possesses a large functional reserve. Empty-sella syndrome is characterised by the appearance of an empty sella and features of panhypopituitarism. Tumours of the anterior pituitary are more common than those of the posterior pituitary and hypothalamus. The adrenal glands lie at the upper pole of each kidney. Cushing’s syndrome is caused by excessive production of cortisol. Conn’s syndrome is an uncommon syndrome occurring due to overproduction of aldosterone, the potent salt-retaining hormone.