Type 2 Diabetes: Living With The Disease: Causes Of High And Low Blood Sugar

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Causes of High and Low Blood Sugar

Even with careful treatment for type 2 diabetes, you may experience periods of high and low blood sugar.

High blood sugar may develop if you:

• Skip a dose of your oral medicine for diabetes or skip a required dose of insulin.
• Eat too much.
• Are feeling a lot of emotional stress or are ill (such as with a severe case of the flu) or have an infection, especially if you are not eating or drinking enough.
• Are taking medicines that can raise blood sugar levels as a side effect, such as sleeping pills, some anti-inflammatory medicines (corticosteroids), and some decongestants.

If you take insulin, you may have some mornings when your blood sugar level is very high. This could happen because of the Somogyi effect. Talk with your health professional if this occurs.

Low blood sugar is not likely to develop unless you take insulin or some oral medicines for type 2 diabetes. Low blood sugar may develop if you:

• Take too many doses of your oral medicine in a day, take the doses too close together, or take your full dose of medicine when you are not going to eat your usual amount of food.
• Exercise too much without eating enough food.
• Skip a meal.
• Drink too much alcohol, especially on an empty stomach.
• Take other medicines that can lower blood sugar levels, such as large doses of aspirin and medicines for psychiatric disorders.
• Have reduced kidney function.
• Develop other endocrine problems, such as Addison's disease or hypothyroidism.

Last updated:	August 14, 2007
Author:	Caroline Rea, RN, BS, MS
Reviewed By:	Caroline S. Rhoads, MD - Internal Medicine, Matthew I. Kim, MD - Endocrinology & Metabolism
Editors:	Susan Van Houten, RN, BSN, MBA, Pat Truman, MATC