Lessons of endocrinology are focused on most frequent endocrinopathies found in clinical practice: diseases of thyroid gland (thyroiditis, nodule and goiter), adrenal gland (hypo- and hyperfunction of the gland), pituitary (hypo- and hyperfunction of the gland), and female gonads (hypogonadism). In addition, it will be discuss pathophysiologic and clinical aspects of disorders of endocrine pancreas (type 1 and type 2 diabetes mellitus), with particular emphasis to diagnostic criteria in general population and in pregnant women, and complications (chronic and acute) caused by diabetes.