UNLABELLED: Decrease of blood glucose levels below 3 mmol/l is in fully developed cases accompanied by neuroglycopenic symptoms that may even lead to altered state of consciousness. The treating physician frequently faces a complicated situation. This may be due to inappropriately administered drugs including cases motivated by self-harm intentions (insulin, insulin secretagogues), or alcohol abuse. Undernourished people, or those afflicted with a serious systemic infection, end-stage liver or kidney diseases or with a failing heart, belong to a risk group. Hypoglycemia typically accompanies hypocorticism (Addisons disease) or lack of glucagon. Endogenous hyperinsulinism caused by a hormonally active pancreatic cancer, that is, by a neuroendocrine tumour - insulinoma, is a possibility to be considered. A hidden cause of hypoglycemias may be a pancreatic-beta- cell dysfunction (nesidioblastosis, or non-insulin pancreatogenous hypoglycemia). A similar situation may arise following gastric bypass surgery. Hypoglycemia incited by the presence of antibodies to insulin or its receptor is cited in literature as a very rare problem. One section in the differentially diagnostic thinking is dedicated to hypoglycemic states accompanying neoplastic, malign processes. Insulin is demonstrably not a responsible agent here, it is a polypeptide structurally close to it, a somatomedin abbreviated as IGF2. KEY WORDS: endoscopic ultrasound pancreatography (EUPG) - hypoglycemia mediated by tumour cells other than β cells (NIPHS) - insulin-like growth factor (IGF1, IGF2) - pro-insulin-like growth factor IGF2 (pro-IGF2).