Excitability

• Heart palpitations, racing heartbeat, anxiety, tremors and shaking can occur when blood sugar drops.
  
  

Altered Mental States

• When blood sugar is low, there isn't enough fuel to allow the brain to function properly. Appearing drunk, staring into space, lethargy and refusing to talk are all signs of acute hypoglycemia that may mimic signs of stroke, epilepsy or a brain aneurysm.
  
  

Psychiatric Problems

• Agitation, combativeness and confusion are relatively common in acute hypoglycemia. According to the Department of Psychiatry at the Nassau University medical center, seven percent of patients who are seen in the E.R. for psychiatric problems actually have acute hypoglycemia as the root cause of their ailments.
  
  

Vomiting

• Young children with ketotic hypoglycemia will often vomit first thing in the morning. This is not a common symptom of hypoglycemia in adults.
  
  

Unconsciousness and convulsions

• If untreated, low blood sugar can cause blackouts and grand mal seizures.