4 Surprising Reasons for Blood Sugar Swings

Food isn't the only thing that can affect blood sugar levels.

Medically Reviewed by Brunilda Nazario, MD on June 23, 2014
From the WebMD Archives

Managing diabetes means being prepared for unexpected blood sugar changes. Certain foods and drinks are often to blame, but not always. Seemingly simple facts of everyday life can sometimes kick your sugar out of whack, too.

Stress. When you're under stress, certain hormones send nutrients, including sugar, into the bloodstream to prepare your body for action. For people with diabetes, that stress response can equal a spike in blood sugar. It can also trigger poor eating habits, whether it's eating too little or eating too much.

Do you suspect stress raises your blood sugar? Every time you check your sugar for the next 2 weeks, rate your stress on a scale from one to 10 and write down both your rating and your blood sugar. If you see a connection between the two, it's time to manage your stress.

"Find some time that's just yours. Take a walk, ride a bike, or take regular breaks to unwind," says Linda M. Siminerio, RN, PhD, CDE. She's the director of the University of Pittsburgh Diabetes Institute.

Tossing and Turning. "Sleep disorders, lack of sleep, and interrupted sleep can raise blood sugars," says Pamela Allweiss, MD, MPH. She's a medical officer in the division of diabetes translation at the CDC. People with diabetes who have trouble falling asleep or who wake up in the night several times a week have higher fasting blood sugar than those who get a better night's sleep. If you have insomnia, get it treated.

Sick Days. Cold, flu, or any infection is a physical stress that can hike blood sugar just like mental stress. To top it off, the sugar and alcohol in some cold medicines can boost blood sugar, while the illness itself can kill your appetite and bring your levels down.

When you're sick, check your blood sugar every 2 to 4 hours, and test your blood or urine for ketones (substances that are made when the body breaks down fat for energy). Stay hydrated with lots of clear fluids, and follow your usual meal plan and medications. If you can't keep food down, drink plenty of fluids, get 15 grams of carbohydrates every hour, and call your doctor.

Take every chance to prevent illness in the first place, Allweiss says. "Get vaccines for as many vaccine-preventable conditions as possible -- flu, pneumonia, hepatitis B, shingles."

Medications for Other Conditions. Some medications for non-diabetes conditions can step up your sugar. For example, certain diuretics prescribed for high blood pressure cause you to lose potassium when you pee, which in turn can raise blood sugar. Antidepressants and antihistamines can cause weight gain and may spike blood sugar. Corticosteroids, such as prednisone and cortisone, treat inflammatory conditions including vasculitis, myositis, and rheumatoid arthritis -- but they can also raise blood sugar. Discuss all your medications with your doctor to make sure they won't affect your levels.

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Pamela Allweiss, MD, MPH, medical officer in the division of diabetes translation at the Centers for Disease Control and Prevention.

Linda Siminerio, RN, PhD, CDE, professor of medicine; executive director, University of Pittsburgh Diabetes Institute.

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