Endocrine diseases are disorders of the endocrine system. The branch of medicine associated with endocrine disorders is known as endocrinology. Endocrine disorders can usually be divided into three categories: endocrine gland hyposecretion (leading to hormone deficiency), endocrine gland hypersecretion (leading to hormone excess) and tumours of endocrine glands. Endocrine disorders involve a mixed picture of hyposecretion and hypersecretion. Endocrine Diseases serves as an essential start to master the science and art of clinical practice and is going to discuss endocrine diseases.