Catching a Cold Can Increase Your Blood Sugar Levels—Here's What to Do to Help
You may notice your blood glucose is on the rise when you’re under the weather. Here’s what’s going on—and how you can take care of yourself.
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Reviewed by Dietitian Emily Lachtrupp, M.S., RD
Blood sugar spikes don’t just happen after eating a carb-rich meal. There are plenty of other reasons your blood sugar might be high. Believe it or not, having a cold or infection might be one of them. That’s because when you get sick, your body releases certain hormones to fight the infection, which impacts your blood glucose levels. Keep reading to learn more about how being sick can impact your blood sugar and what you can do to prevent spikes when you’re not feeling your best.
Related: The #1 Habit You Should Break for Better Blood Sugar Balance, According to a Dietitian
How Does Illness Affect Blood Sugar Levels?
When you get sick, your body triggers a cascade of responses to fight off the infection. For example, stress hormones like cortisol and epinephrine are released, according to the Endocrine Society. Your body needs more energy during this time—battling an illness is tough work—and these hormones cause blood sugar to rise in order to meet this demand.
However, the extra stress hormones also reduce insulin, the hormone responsible for moving glucose from your blood into your cells. Without adequate insulin, glucose stays in your bloodstream longer and blood sugar levels rise. In folks without diabetes, this typically isn’t a problem, but it can contribute to conditions like hyperglycemia in people who have diabetes.
Understanding the Relationship Between Colds and Blood Sugars
For those with diabetes, the rise in blood sugar during an infection can be more dangerous since your body already has a harder time keeping your blood sugar in check. Plus, your lifestyle understandably changes when you’re sick. You may be more inclined to skip meals and exercise, which can make it more challenging to manage your blood sugar levels.
With less insulin production and higher blood sugar, you’re also at an increased risk of diabetic ketoacidosis (DKA) during a cold or infection, per the Centers for Disease Control and Prevention. In fact, research shows that infection is one of the most common causes of this diabetes complication, per a 2023 study in Annals of Medicine & Surgery. DKA happens when your body doesn’t have enough insulin to move glucose from your bloodstream to your cells, so it turns to fat for energy. Breaking down fat for energy produces ketones, which can become dangerous when too many are produced too fast.
You can use an over-the-counter test to check for ketones in your urine or a meter to test ketone levels in your blood. If you have diabetes, the CDC recommends taking a test every four to six hours while sick to be sure they’re within normal range. If you’re concerned you may have ketoacidosis or elevated ketone levels, call your doctor right away—DKA is a medical emergency.
Managing Blood Sugar Levels During a Cold
To prevent cold-related blood sugar spikes or dips, follow these important strategies:
Check your blood sugar regularly. If you get a cold or infection and you have diabetes, your doctor will often recommend keeping a closer eye on your blood glucose. This can help you take action as needed, such as adjusting your meals or snacks. Seek medical care if blood sugars go too high or low.
Stay on top of medications. If you take diabetes medication or insulin, make sure that you have enough on hand in case you get sick. (It can be challenging to pick up a refill when you don’t feel well.) In addition, keep up with your medication regimen during illness, and contact your doctor if you have questions about dosages.
Try to eat regular meals. While your appetite might go down when you’re sick, skipping meals could cause your blood sugar to drop too low. Do your best to keep up with regular meals and snacks. Staying nourished also gives your body energy to fight the infection.
Stock up on easy-to-prep foods. The CDC advises drinking or eating 50 grams of carbohydrates every four hours when you’re sick. Cooking and eating during illness can be tough, so keep nutritious, low-effort foods on hand. Some examples include canned soup, instant oats, crackers, cheese, bread and nut butter. If your appetite just isn’t there, the National Institute of Diabetes and Digestive and Kidney Diseases recommends trying juice, broth, ice pops, milk, yogurt or even regular soda to help prevent low blood sugar.
Stay hydrated. Drinking fluids is important when you’re ill. In addition, dehydration can also cause blood sugar spikes. Sip water, tea or sugar-free sports drinks.
Go for a walk. As you start to feel better, try gentle forms of movement. According to a 2022 study in Sports Medicine, going for a low-intensity walk after eating has been shown to help lower blood sugar. Aim for a few minutes at first and build up from there as you start to feel like your normal self again.
Bottom Line
Blood sugar levels will often rise during a cold or infection, thanks to the release of stress hormones. For healthy people, this generally isn’t a problem, but for those with diabetes it warrants extra care and attention. If you have diabetes, be sure to keep a close eye on your blood sugar and ketone levels, and do your best to stay nourished and hydrated while sick. We suggest speaking with your health care team for personalized guidance on preparing for and managing colds or infections with diabetes.
It’s also important to do what you can to stay healthy during sickness season. One of the best ways to do that is to get the flu vaccine. Doing so can reduce your chances of infection and reduce the severity of illness should you get sick, something that’s key when you have diabetes and are at a higher risk for developing complications from the flu, says the CDC.
Read the original article on Eating Well.
