Nephrotic syndrome is characterised by proteinuria >3.5 g/24h, oedema, hypoalbuminaemia and hyperlipidaemia. Several glomerular diseases, either primary or secondary, may lead to nephrotic syndrome. Investigations for nephrotic syndrome include immunological and infectious evaluations. Renal biopsy is often mandatory, except in diabetes. Depending on aetiology specific treatment, often with immunosuppressive agents, may be implemented. In any cases nonspecific treatment should be started with ACE inhibitors or ARBs. Urinary protein loss leads to several complications: water and sodium retention, hyperlipidaemia, increased risk of thromboembolism and infection, anaemia and alteration of mineral metabolism. Each of these complications must be identified.