Classification of Hypoglycaemia There are many ways of classifying hypoglycaemia clinically; the most useful is into fasting hypoglycaemia and stimulative hypoglycaemia. The former, as its name implies, occurs during fasting, but may also result in response to a specific stimulus. Stimulative hypoglycaemia occurs only in response to a stimulus such as a drug, or as a reaction to alimentary hyperglycaemia. In this context, starvation, but not simple fasting, is a ‘stimulus’ to hypoglycaemia.