Symptoms resulting from low blood glucose (normal glucose range 60-100 mg/dL (3.3 to 5.6 mmol/L)) which are either autonomic or neuroglycopenic. Autonomic symptoms include sweating, trembling, feelings of warmth, anxiety, and nausea. Neuroglycopenic symptoms include feelings of dizziness, confusion, tiredness, difficulty speaking, headache and inability to concentrate.