How Does an Infection Increase Blood Sugar in Diabetics?

When a person has diabetes, infection is cause for concern. Even everyday infections such as the common cold can cause blood glucose levels to increase. Infection is a challenge that requires careful blood glucose monitoring and proper medical care.


When struck by infection, the body releases stress hormones that help it fight the infection but at the same time cause an increase in blood glucose. Insulin resistance also increases, causing a further rise in glucose levels by impairing the body's ability to use glucose for energy.


Doctors and diabetes educators recommend having a sick-day plan for managing common infections at home. Part of a sick-day plan is knowing how often you should test your blood glucose when you're not feeling well. Ask you doctor if you also need to test your urine for ketones when you're sick. Staying hydrated is important since dehydration can occur when blood glucose levels are too high. A sick-day plan includes knowing when to call your doctor or seek emergency treatment, as well as how to maintain your usual carbohydrate intake when you don't feel like eating your normal foods. If you use insulin, work with your health-care team to make a plan for adjusting dosage to control elevated blood glucose levels.


Some studies indicate that people with diabetes are at higher risk for certain types of infection, such as urinary tract infections and yeast infections. Existing high blood glucose levels in the body create an environment where certain micro-organisms can thrive. In addition, diabetes can cause a person to get sick when she gets an infection, such as the flu or pneumonia. For this reason, the U.S. Centers for Disease Control recommend that people with diabetes be vaccinated for influenza, pneumococcal pneumonia and tetanus/diphtheria 5.

Learning More

Your health-care team can help you learn about the signs and symptoms of infection and to make a sick-day plan. Always consult your doctor if you suspect an infection and for advice on how to take care of it. Your doctor may recommend a visit with a diabetes educator, who can help you learn about ways to manage your diabetes and make a plan for managing special situations.