Hypoglycemia is a pathological state of the human body, and many diseases and drugs may lead to hypoglycemia. Long-term hypoglycemia may also lead to many other diseases: First, when hypoglycemia, the body’s sympathetic nerve excitability increases, cardiac oxygen consumption increases, the myocardium manifests itself in relative ischemia and hypoxia, which may induce or exacerbate coronary artery disease, cardiac arrhythmia, cardiac failure and so on on top of the original disease. Second, when hypoglycemia, no matter through the diet to return to normal, or the human body to start its own glucose response, may lead to a great fluctuation of blood glucose in the short term, the long-term will be on the human body many organs of the function of the damage, such as vascular endothelial damage, the emergence of large blood vessels and microvascular lesions. Third, long-term repeated hypoglycemia has a great impact on brain function, which can lead to dementia, personality abnormalities, neuropsychiatric symptoms and diseases.