Johns Hopkins Health Alerts | Diabetes | How To Control Blood Glucose Levels During an Illness

Getting sick (even a cold or flu) can trigger a rise in blood glucose levels. Knowing what steps to take to control glucose can help you feel better and stay in good control!

People with diabetes must be especially careful when suffering from an illness like a cold or the flu. Illness not only affects your eating, sleeping, and exercise—habits closely linked to blood glucose control—it may cause the liver to make and release glucose into the bloodstream. This increase in glucose released from the liver provides extra energy to combat the stress of an illness, but in people with diabetes it can cause blood glucose to rise too high, whether you are eating or not.

At the same time, an illness decreases the sensitivity of cells to insulin and makes it more difficult for these cells to remove glucose from the bloodstream. A person without diabetes can produce extra insulin to help the additional glucose enter cells. But people with diabetes are less able to produce extra insulin or respond to it effectively. The resulting rise in blood glucose increases the risk of diabetic ketoacidosis in people with type 1 diabetes and hyperosmolar nonketotic state in those with type 2 diabetes.

To prevent these serious complications, as well as to minimize fluctuations in blood glucose levels, follow these sick-day precautions.

• Inform your health care professional when you become sick and have diabetes. This precaution is particularly important if you are unable to eat regular foods, have diarrhea or vomiting for more than six hours, or have had a fever for a couple of days that is not improving.

• Follow the treatment plan for the sickness. For example, take any necessary medications, such as antibiotics for an infection, according to schedule. If you are treated by a doctor you have never seen before, make sure he or she is aware that you have diabetes.

• Test blood glucose levels more often than usual. If you have type 1 diabetes, test blood glucose and urine ketone levels every four hours, even during the night. (Set an alarm clock or have someone wake you up.) If you have type 2 diabetes, testing blood glucose levels four times during the day is probably enough; if blood glucose levels exceed 250 mg/dL, test urine for ketones. Call your health care professional if blood glucose levels are consistently above 250 mg/dL and are accompanied by ketones in the urine.

• Take your diabetes medication as usual, unless, of course, your health professional advises otherwise. Being sick causes blood glucose levels to rise, even if you are not eating.

• If you use insulin, keep a bottle of rapid- or very rapid-acting insulin handy. You should take this precaution even if you do not take these types of insulin regularly. Use the rapid- or very rapid-acting insulin if your health professional tells you to take an extra sick-day dose or if you need to lower blood glucose levels quickly.

• Watch for any symptoms of dehydration, ketoacidosis, or hyperosmolar nonketotic state. The symptoms of dehydration include dry mouth, cracked lips, and dry or flushed skin. Contact your health professional if any of these symptoms occur.

• Prevent dehydration by drinking plenty of liquids. You should consume at least one large (8 oz.) glass of clear fluid each hour while awake. If your usual diet is not disrupted by the illness, drink water, tea, broth, or other sugar-free beverages. If you are unable to eat meals, alternate sugar-containing fluids with those that are sugar-free.

• Try to consume a normal amount of carbohydrates. Eating many small portions throughout the day may help. Eat easy-to-digest foods such as gelatin, crackers, soup, and applesauce.

• Rest as much as possible. If necessary, get someone—such as a family member or friend—to help care for you.

Johns Hopkins Health Alerts | Diabetes | How To Control Blood Glucose Levels During an Illness