A system for adjusting blood glucose level including an insulin delivery device configured to release insulin into the body of a person, and an EEG monitor having an EEG sensing part including EEG electrodes. The EEG monitor can be arranged in the ear region of the person with the EEG sensing part arranged subcutaneously at the scalp or arranged in the ear canal. The EEG monitor includes an EEG signal processor arranged at the ear and adapted for identifying onset of hypoglycemia. The system further includes a wireless link between the EEG monitor and the insulin delivery device. The EEG monitor is configured to submit a warning signal to the insulin delivery device if an upcoming onset of hypoglycemia is identified. The warning message will cause the insulin delivery device to restrict insulin delivery for a predetermined time, and a warning is provided to the person or to a caregiver.
