Both headaches and sudden irritability are symptoms of low blood sugar: http://www.nhs.uk/Conditions/Hypoglycaemia/Pages/Symptoms.aspx http://www.nhs.uk/Condit

Both headaches and sudden irritability are symptoms of low blood sugar: http://www.nhs.uk/Conditions/Hypoglycaemia/Pages/Symptoms.aspx http://www.nhs.uk/Conditions/Hypoglycaemia/Pages/Symptoms.as...