Headache can occur without eating. Not eating can generally cause hypoglycemia, and in severe hypoglycemia can cause ischemia and hypoxia in the brain, and patients with severe ischemia and hypoxia in the brain can develop headache. Dizziness, nausea, vomiting, balance disorders and ataxia may also occur, as well as nystagmus and diplopia. Some patients may experience blackness in front of the eyes, and may also experience weakness of the limbs, sensory disorders of the lateral limbs and motor disorders. In severe hypoglycemia, patients may have palpitations, chest tightness, shortness of breath, or they may have coldness of the limbs or trembling and sweating of the limbs. If patients have hypoglycemia, they should be given timely correction, either by intravenous pushing of hypertonic glucose or by oral administration of sugar cubes and sugar saline, to prevent severe hypoglycemia from causing hypoglycemic encephalopathy. Because hypoglycemic encephalopathy can make the patient have inattentiveness and lax thinking.