High blood sugar (hyperglycemia) in
diabetes occurs when the sugar (glucose) level in the
blood rises above normal. For a person who has diabetes, high blood sugar may
be caused by not getting insulin, missing your diabetes medicine, eating too much food, skipping exercise, or being ill or
Unlike low blood sugar, high blood sugar usually develops
slowly over hours or days. Blood sugar levels well above your target range may
make you feel tired and thirsty. If your blood sugar level stays higher than
your target range, your body will adjust to that level. If your blood sugar continues to
rise, your kidneys will produce more urine and you can become
dehydrated. Signs of dehydration include being thirstier than usual and having darker urine than usual. If you become severely dehydrated, you can
go into a coma and possibly die. Over time, high blood sugar damages the eyes,
heart, kidneys, blood vessels, and nerves.
Unless you fail to
notice the symptoms, you usually have time to treat high blood sugar so that
you can prevent an emergency. Three things can help you prevent high blood
- Test your blood sugar often, especially if you
are sick or not following your normal routine. You can see when your blood
sugar is above your target range, even if you don't have symptoms of high blood
sugar (increased thirst, increased urination, and fatigue). Then you can treat
- Call your doctor if you have frequent high blood sugar or
your blood sugar is consistently above your target range. Your medicine may
need to be adjusted or changed.
- Drink extra water or
noncaffeinated, nonsugared drinks to prevent dehydration.
What is a high blood sugar emergency?
Why do you need to treat high blood sugar?
How do you prevent high blood sugar emergencies?
Where to go from here