What Causes Hyperglycemia?
A number of things can cause hyperglycemia:
If you have type 1, you may not have given yourself enough insulin.
If you have type 2, your body may have enough insulin, but it is not as effective as it should be.
You ate more than planned or exercised less than planned.
You have stress from an illness, such as a cold or flu.
You have other stress, such as family conflicts or school or dating problems.
You may have experienced the dawn phenomenon (a surge of hormones that the body produces daily around 4:00 a.m. to 5:00 a.m.).
- See more at: http://www.diabetes.org/living-with-diabetes/treatment-and-care/blood-glucose-control/hyperglycemia.html?referrer=https://www.google.co.th/#sthash.NUASNUR5.kPoCBxl0.dpuf