Hypoglycaemia is the most frequent complication of insulin therapy in diabetic patients. Severe hypoglycaemia may impair not only the brain, but also the heart and autonomie nervous systém. Frequent episodes cause a failure of the autonomie nervous response to a falling blood glucose level and also impair its counter regulation. The changes caused by repetitive hypoglycaemia deepen the autonomie failure and lead to more and more frequent episodes. This phenomenon has been called „hypoglycaemia-associated autonomie failure (HAAF)". Its pathophysiological mechanisms háve been deseribed but there is still a need for its clinical assessment. The exact evaluation of the frequency and seriousness of hypoglycaemia, as well as the autonomie nervous impairment, is essential for the selection of further treatment procedures. For this rea-son a scoring systém has been developed. Transplantation of either the islet of Langerhans or panereas has been proven to be the best treatment of HAAF. A functioning graft ensures long-term euglycaemia or at least improves unstable glycaemia. The fundamental prerequisite for HAAF treatment is several weeks without hypoglycaemia.

        Key words: hypoglycaemia, diabetes mellitus, autonomie nervous systém, transplantation