The symptoms that cause hypoglycemia come from two main sources: autonomic nervous system hypoglycemia symptoms and neuronal hypoglycemia symptoms in the brain. Autonomic nervous system hypoglycemia symptoms: including tremor, palpitations, anxiety, as well as sweating, hunger and abnormal sensation, these symptoms are largely caused by sympathetic activation rather than adrenal medullary activation. They will disappear on their own with sugar supplementation. Symptoms of neuronal hypoglycemia in the brain: These include cognitive impairment, behavioral changes, psychomotor abnormalities, and seizures and coma at even lower blood glucose concentrations. Although severe, prolonged hypoglycemia can lead to unnoticed brain death in diabetics, the vast majority of hypoglycemic episodes can be reversed when glucose levels rise to normal. The rare fatal seizures are usually thought to be the result of hypoglycemia-induced arrhythmias. Signs of hypoglycemia: Pallor and sweating are common signs of hypoglycemia. Heart rate and systolic blood pressure rise, but the rise is not great. Autonomic manifestations of hypoglycemia are often observed, and transient neurological deficits occasionally occur. Permanent neurological damage can be seen in patients with long-term recurrent hypoglycemia and in patients with a single episode of severe hypoglycemia that is not corrected in time. Therefore, most patients with hypoglycemia do not have serious clinical symptoms and are reversible, but some cases may still cause irreversible damage and still need to be detected and treated promptly.