FreeStyle Libre Glucose Monitoring System Paediatric Study

Inclusion Criteria: * Aged ≥4 years and ≤17 years. * Has an identified Caregiver of ≥18 years. * Type 1 diabetes using insulin (administered by injections or CSII) for at least 1 year. * Current insulin regimen has been unchanged for at least 2 months prior to enrolment (e.g. change of insulin or administration method), with no plans to change insulin regimen. * Currently testing BG, on average at least 2 times per day. Exclusion Criteria: * Concomitant disease or condition that may compromise patient safety including and not limited to; cystic fibrosis, severe mental illness, known or suspected eating disorder or any uncontrolled long term medical condition. * Currently prescribed oral steroid therapy for any acute or chronic condition (or requires it during the study). * Currently receiving dialysis treatment or planning to receive dialysis during the study. * Female participant known to be pregnant. * Participating in another device or drug study that could affect glucose measurements or glucose management. * Currently using or planning to use FreeStyle Libre Flash Glucose Monitoring System or a Continuous Glucose Monitoring (CGM) device during the study. * Has used the FreeStyle Libre Flash Glucose Monitoring System or a Continuous Glucose Monitoring (CGM) device in the previous 3 months. * Known (or suspected) allergy to medical grade adhesives. * In the investigator's opinion the participant is unsuitable to participate due to any other cause/reason (participant and caregiver considered).