Low blood sugar means hypoglycemia. Pallor and sweating are common signs of hypoglycemia. Hypoglycemia can easily cause sympathetic excitation of adrenal glands and symptoms such as anxiety, tremor, palpitation and hunger, or even may lead to hemodynamic changes, including tachycardia, increased pulse pressure, paroxysmal convulsions, cognitive impairment, coma, etc. 1. Sympathetic excitation symptoms: Hypoglycemia can easily stimulate increased secretion of adrenaline, and hypoglycemia syndrome can occur, which can be manifested as pale face, palpitation, cold limbs It can be manifested as pale face, palpitations, cold sweat, hand trembling, leg weakness, weakness around the body, dizziness, blurred eyes, hunger, panic and anxiety, etc., which can be relieved after eating; 2. Cortical inhibition symptoms: severe cases may have disorders of consciousness, which can be manifested as drowsiness, tremor, impaired memory, headache, apathy, depression and other states, and in serious cases, dementia may appear; 3. Subcortical central inhibition symptoms: patients may have confusion, agitation, even the presence of tonic convulsions, and positive cone bundle signs, which may manifest as hemiparesis, light paralysis, aphasia and monoparesis. Involvement of cerebral tissue structures such as the cerebellum is mostly manifested as tremor and torsional spasms.