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High blood sugar in
diabetes occurs when the sugar (glucose) level in the
blood rises above normal. It is also called hyperglycemia. When you have diabetes, high blood sugar may
be caused by not getting enough insulin or missing your diabetes medicine. It may also be caused by eating too much food, skipping exercise, or being ill or
Unlike low blood sugar, high blood sugar usually happens
slowly over hours or days. Blood sugar levels above your target range may
make you feel tired and thirsty. If your blood sugar keeps rising, your kidneys will make more urine and you can get
dehydrated. Signs of dehydration include being thirstier than usual and having darker urine than usual. Without treatment, severe dehydration can be life-threatening. Over time, high blood sugar can damage the eyes,
heart, kidneys, blood vessels, and nerves.
Watch for symptoms of high blood sugar. Symptoms include feeling very tired or thirsty and urinating more often than usual. As long as you
notice the symptoms, you will probably have time to treat high blood sugar so that
you can prevent an emergency. Three things can help you prevent high blood
Infections that aren't treated (such
as urinary tract infections, pneumonia, and skin infections) can raise your
risk for a high blood sugar emergency.
The best way to
prevent high blood sugar emergencies is to treat high blood sugar as soon as
you have symptoms or when your blood sugar is well above your target
range (for example, 200 mg/dL or higher).
If your blood sugar levels
are above your target range, drink extra liquids. This helps replace the fluids lost
through your urine. Water and sugar-free drinks are best. Avoid caffeinated drinks,
alcohol, and soda pop. And avoid other drinks that have a lot of sugar, such as fruit juice.
Other Works Consulted
Inzucchi SE, et al. (2012). Management of hyperglycemia in type 2 diabetes: A patient-centered approach. Diabetes Care, 35(6): 1364–1379.
Inzucchi SE, et al. (2015). Management of hyperglycemia in type 2 diabetes, 2015: A patient-centered approach: Update to a position statement of the American Diabetes Association and the European Association for the Study of Diabetes. Diabetes Care, 38(1): 140–149. DOI: 10.2337/dc14-2441. Accessed February 18, 2015.
Kitabchi AE, et al. (2009). Hyperglycemic crises in adult patients with diabetes. Diabetes Care, 32(7): 1335–1343.
ByHealthwise StaffPrimary Medical ReviewerE. Gregory Thompson, MD - Internal MedicineKathleen Romito, MD - Family MedicineSpecialist Medical ReviewerRhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator
Current as ofMay 22, 2015
Current as of:
May 22, 2015
E. Gregory Thompson, MD - Internal Medicine & Kathleen Romito, MD - Family Medicine & Rhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator
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