Symptoms of low blood sugar (hypoglycemia) in babies are often difficult to identify because they are similar to some normal baby activities. Common symptoms include irritability, sleepiness, lethargy, excessive hunger and rapid heart rate. More severe symptoms, such as seizures and coma, can occur with a prolonged low blood sugar or an extremely low blood sugar.
Common symptoms of low blood sugar in older children and adults include feelings of shakiness, weakness, or tiredness, confusion and rapid pulse. More severe symptoms include seizures or coma.