Type 1 Diabetes And The Flu (And Other Illnesses)

Being sick is never fun, but for people with type 1 diabetes (T1D) it can pose extra problems. When a person gets sick, their body is under stress. During times of mental or physical stress, like when sick with the flu or a serious infection, the body makes and releases stress hormones to fight illness and blood sugar can be affected. On these days, you will need to monitor your blood sugar very closely. 

The best way to combat this is, of course, by not getting sick in the first place. That means getting a flu shot every year, as well as making sleep and hydration a priority and washing hands often. But a cold can still catch a person at any time. Since being sick can pose a serious risk for people with type 1 diabetes, it’s critical to have a plan of action in place. 

Have this short list of things to do when you are sick, keep it handy so you are prepared:

  • Check your blood sugar every 2-4 hours 
  • Drink plenty of fluids, especially water to stay hydrated 
  • Check for ketones 
  • Never stop insulin completely 
  • Contact your diabetes care team if you have vomiting, moderate or large ketones, symptoms of diabetic ketoacidosis (DKA)

How to Read Your Levels When Sick

When you’re under the weather, it’s crucial to carefully monitor your blood sugar and ketones more often than usual, as often as every four hours. Check your continuous glucose monitor (CGM) if you have one, or frequently use finger sticks. It may be necessary to take extra insulin to bring down higher blood sugar levels. 

The impact of illness on your blood sugar is also dependent on the type of illness you have: 

For a relatively minor viral illness such as a cold or chicken pox: You should not see a major effect on your blood sugar level, though you should still keep an eye on it. 

For a gastrointestinal infection such as the flu: If you get sick with flu-like symptoms, there are more serious effects. You are less likely to produce stress hormones. It is important to keep up your fluids by drinking one to two glasses of fluid every hour or so. In the case of gastrointestinal infection, your blood sugar levels are more likely to be low because you’re not eating, or you’re not absorbing the food that you are eating. 

For a serious viral or bacterial infection: If your blood sugar levels are high or you have a fever, you are especially prone to becoming dehydrated and need to maintain your fluid intake. If you are feeling particularly ill, test your blood sugar levels more frequently. You should also test either your blood or your urine for ketones. 

A note about ketones when sick: Elevated ketone levels often occur when blood sugar readings are high. This can be a sign that the body is using fat and muscle for energy, instead of sugar. Be on the lookout for ketones, as very high levels could lead to diabetic ketoacidosis (DKA), a dangerous condition that demands immediate medical attention, and can be fatal if left untreated.

How Do Medications Affect Type 1 Diabetes?

When you feel sick, it is more important than ever to continue a normal schedule of medications, even if you’re having a hard time keeping food and liquid down. 

Many over-the-counter (OTC) medications can affect blood sugar levels and though there are some sugar-free cough syrups on the market, many such syrups contain sugar, which only exacerbates already high blood sugar levels. That’s why pills that are taken orally—that have the same ingredients as syrups—can be a better choice if they contain no carbohydrates. Other drugs like decongestants raise blood sugar, while aspirin can, in large doses, lower blood sugar levels. 

Be aware of the effects of pain and fever reducers, too. Acetaminophen, which helps counteract minor aches and fevers associated with the flu or a cold, can cause false or no readings in CGMs, and be toxic to the liver and kidneys. Anyone with kidney complications should be cautious about using these drugs. Ibuprofen increases the hypoglycemic effects of insulin and should also be handled with care.

Your Diet When Sick

Because it can be difficult to stick to your normal meal plan when feeling unwell, it’s good to have on hand food that you know will help keep up your carbohydrate intake in a healthy way. Foods like crackers, vegetable or noodle soups, unsweetened applesauce, or fruit-flavored yogurt are all easy-on-the-stomach go-tos. If even those mild foods prove difficult to swallow, then liquids are a good short-term option. 

If blood sugars are in range, you can start with drinks that contain carbohydrates, and plan to consume something every three to four hours. What kind of drinks? Fruit juices such as orange or cranberry, sports drinks and regular soft drinks are all good options. Staying well-hydrated is key, especially when ketones are present as it can help flush them out. Look to carb-free choices like water, broth, sugar-free gelatin, popsicles or soft drinks. 

The flu and other illnesses can have serious effects on those with type 1 diabetes. Don’t hesitate to call your doctor or go to a hospital emergency room. Find advice and tips on hospital visits here.