In iOS 8.2, you can manually enter and view blood glucose values in mg/dL (milligrams per deciliter) or in mmol/L (millimoles per liter). To change units, open Health and go to Health Data > Results > Blood Glucose > Unit. Make sure to choose the same units that your measurement device uses.
If you don't see blood glucose options in Heath, check for an iOS update.
If you see any previous blood glucose values in your Health app that don’t look right, you can tap Edit and delete them.