Note: This article is for educational purposes and should not replace personal medical advice. People with diabetes should work with their healthcare team to create a sick-day plan that fits their medications, glucose targets, age, kidney function, pregnancy status, and overall health.

Flu and COVID-19 are nobody’s idea of a relaxing weekend, but for people with diabetes, they can be more than an inconvenient pile of tissues and soup bowls. Illness can push blood sugar up, pull it down, trigger dehydration, interfere with eating, complicate medication routines, and make decision-making feel like solving a crossword puzzle while wearing oven mitts.

The good news? Preparation works. A smart diabetes sick-day plan can help you respond quickly, avoid dangerous blood sugar swings, and know when to call your doctor before “I’ll wait and see” turns into “Why is everyone looking worried?” Whether you live with type 1 diabetes, type 2 diabetes, gestational diabetes, or care for someone who does, preparing for flu and COVID-19 is less about panic and more about having the right plan, supplies, and phone numbers ready before the thermometer beeps.

Why Flu and COVID-19 Matter More When You Have Diabetes

Diabetes does not automatically mean you will catch every virus that strolls through town wearing a tiny villain cape. However, when people with diabetes do get sick, they may have a higher risk of complications, especially if blood glucose is running high or other conditions are present, such as heart disease, kidney disease, obesity, older age, or a weakened immune system.

During infection, the body releases stress hormones to fight illness. Those hormones can make insulin work less effectively, causing blood glucose to rise. At the same time, fever, vomiting, diarrhea, poor appetite, and dehydration can make blood glucose unpredictable. In other words, flu and COVID-19 can turn diabetes management from a quiet spreadsheet into a group chat with 47 unread messages.

For some people, especially those with type 1 diabetes or insulin-dependent type 2 diabetes, illness can increase the risk of diabetic ketoacidosis, also called DKA. This serious condition can happen when the body does not have enough insulin and begins breaking down fat too quickly, producing ketones. DKA can become life-threatening and requires urgent medical care.

Step One: Build a Diabetes Sick-Day Plan Before You Need It

The best time to make a sick-day plan is when you are not sick. Once fever, chills, coughing, fatigue, and “Where did I put my glucose meter?” enter the room, decision-making becomes much harder. Your plan should be written down, easy to find, and shared with at least one trusted person.

What Your Sick-Day Plan Should Include

A practical diabetes sick-day plan should answer several key questions: How often should you check blood glucose? When should you check ketones? Which medications should you continue? Which medicines might need adjustment? What should you eat if you cannot handle regular meals? When should you call your healthcare provider? When should you seek urgent care?

Ask your diabetes care team for specific instructions. This is especially important if you use insulin, a continuous glucose monitor, an insulin pump, sulfonylureas, SGLT2 inhibitors, GLP-1 medications, or medicines for blood pressure, heart disease, or kidney disease. Medication rules during illness can vary from person to person. A neighbor’s advice may be heartfelt, but your pancreas does not take community suggestions.

Step Two: Stock a Sick-Day Kit

A sick-day kit is not glamorous. It will not win design awards. But when you feel awful, a well-stocked kit can feel like a tiny pharmacy fairy moved into your cabinet.

Your kit should include a working thermometer, glucose meter supplies, CGM supplies if you use one, extra batteries or chargers, ketone strips or a blood ketone meter if recommended, rapid-acting carbohydrates, electrolyte drinks or oral rehydration solution, low-sugar fluids, easy-to-digest foods, fever reducers approved by your clinician, tissues, masks, hand sanitizer, and at-home COVID-19 tests that have not expired.

Keep several days to several weeks of diabetes medications and supplies on hand when possible. Include insulin, syringes, pen needles, pump supplies, alcohol swabs, lancets, test strips, glucagon if prescribed, and a printed medication list. Also keep your doctor’s phone number, pharmacy number, insurance information, and emergency contact details in the kit. Future-you with a fever will want to send present-you a thank-you card.

Step Three: Stay Current on Vaccines

Vaccination is one of the strongest prevention tools for people with diabetes. Flu vaccination is recommended annually for many people and is especially important for those at higher risk of serious flu complications. COVID-19 vaccine recommendations may change over time, so people with diabetes should check current guidance and discuss timing with their healthcare provider.

Ask your clinician about other vaccines too, including pneumococcal, hepatitis B, shingles, Tdap, and RSV vaccination when age or health status makes them appropriate. Diabetes can increase the risk of complications from infections beyond flu and COVID-19, so prevention should be broader than one shot and a hopeful thumbs-up.

Step Four: Know the Symptoms and Test Early

Flu and COVID-19 can overlap. Both may cause fever, chills, cough, sore throat, fatigue, body aches, headache, and congestion. COVID-19 may also cause loss of taste or smell, though that symptom is less reliable than it was earlier in the pandemic. Some people have stomach symptoms. Others have mild symptoms but still need extra attention because diabetes can raise the risk of severe illness.

Testing helps guide next steps. At-home COVID-19 tests are widely available, and some tests can detect both flu and COVID-19. Follow the package instructions carefully. If an at-home COVID-19 test is negative but symptoms continue, repeat testing as directed because false negatives can occur, especially early in illness.

If you are at higher risk for severe illness, do not wait several days hoping symptoms will “declare themselves” like a dramatic reality-show contestant. Call your healthcare provider early. Treatments for flu and COVID-19 work best when started soon after symptoms begin.

Step Five: Act Fast on Treatment

For flu, antiviral medications work best when started within the first one to two days of symptoms. For COVID-19, antiviral treatment must generally begin within a short window after symptoms start. People with diabetes should ask their clinician in advance what to do if symptoms appear, where to test, and how quickly they can access treatment.

Do not assume treatment is unnecessary because symptoms are mild on day one. Flu and COVID-19 can change quickly, and early treatment may reduce the risk of complications in high-risk patients. Also tell your healthcare provider about all medications and supplements you take, because some COVID-19 treatments can interact with common drugs.

Managing Blood Sugar When You Are Sick

When you are sick, blood glucose can rise even if you are eating very little. This feels unfair because it is unfair. The body is busy fighting infection, releasing hormones that can increase insulin resistance. That means your usual routine may not work the usual way.

Check Glucose More Often

Your care team may advise checking blood glucose every two to four hours during illness, or more often if readings are high, symptoms are severe, you use insulin, or you are at risk for DKA. If you use a continuous glucose monitor, confirm unusual readings with a fingerstick when symptoms do not match the number or when your device suggests rapidly changing glucose.

Check Ketones When Recommended

People with type 1 diabetes, people using insulin, people with a history of DKA, and some people taking SGLT2 inhibitors may need to check ketones during illness. Ketone testing may be recommended when glucose is high, when vomiting occurs, when fever persists, or when you feel unusually weak, nauseated, or short of breath.

Moderate or large ketones are a warning sign. Call your healthcare provider promptly, and seek urgent care if you cannot keep fluids down, have trouble breathing, feel confused, have severe abdominal pain, or have symptoms that are getting worse.

Do Not Stop Insulin Without Medical Guidance

If you take insulin, do not stop it just because you are eating less unless your diabetes care team specifically tells you what to do. Many people need insulin during illness even when meals are small. Basal insulin is especially important for preventing ketones. Your sick-day plan should explain how to handle correction doses, pump settings, missed meals, and low blood sugar.

Hydration: The Unsung Hero of Sick-Day Diabetes Care

Hydration sounds boring until dehydration arrives and starts causing trouble. Fever, sweating, vomiting, diarrhea, and high blood glucose can all drain fluid from the body. Dehydration can make blood glucose harder to manage and may increase the risk of ketones.

Take small, frequent sips if your stomach is unsettled. Water, broth, sugar-free electrolyte drinks, and ice chips may help. If your blood sugar is low or you cannot eat, you may need fluids that contain carbohydrates, such as regular sports drink, juice, or oral rehydration solution, depending on your care plan.

If you cannot keep fluids down for several hours, call your healthcare provider. Waiting too long with vomiting, high glucose, or ketones can become dangerous quickly.

What to Eat When Food Sounds Terrible

Illness can make food about as appealing as chewing a wet envelope. Still, your body needs fluids, carbohydrates, and energy. If you cannot eat regular meals, your care team may recommend small amounts of carbohydrate-containing foods or drinks every few hours.

Useful sick-day foods may include soup, crackers, toast, applesauce, yogurt, gelatin, bananas, oatmeal, rice, popsicles, or smoothies. Keep both low-carb and regular-carb options available because sick days can bring either high or low blood glucose. Diabetes is nothing if not committed to keeping the plot interesting.

Choose Cold, Flu, and Cough Medicines Carefully

Some over-the-counter medicines can affect blood sugar, blood pressure, heart rhythm, or kidney function. Liquid cough syrups may contain sugar. Decongestants may raise blood pressure. Nonsteroidal anti-inflammatory drugs may not be appropriate for some people with kidney disease or certain heart conditions.

Ask your pharmacist or clinician which fever reducers, cough medicines, and congestion treatments are safest for you. Keep the approved list in your sick-day kit so you are not reading tiny medicine labels at midnight while your nose is staging a rebellion.

Protect Your Household

When someone in the home has flu-like or COVID-like symptoms, reduce spread quickly. Stay home when sick. Use masks around others when needed, improve ventilation, wash hands often, clean high-touch surfaces, avoid sharing cups or utensils, and consider separating the sick person from higher-risk household members.

Current respiratory virus guidance emphasizes staying away from others while symptoms are active and returning to normal activities only after symptoms are improving and fever has been gone for at least 24 hours without fever-reducing medicine. Extra precautions for several days afterward can help protect people at higher risk.

When to Call the Doctor

Call your healthcare provider if you test positive for COVID-19 or suspect flu, especially if symptoms started recently and you may qualify for antiviral treatment. Also call if blood glucose stays above your sick-day threshold, ketones are present, vomiting or diarrhea continues, fever persists, you cannot eat or drink, you are unsure how to adjust medication, or symptoms are worsening.

Seek Emergency Help Immediately If You Have:

• Trouble breathing or chest pain
• Confusion, fainting, or severe weakness
• Blue or gray lips, face, or nails
• Signs of severe dehydration
• Moderate or large ketones with illness symptoms
• Repeated vomiting and inability to keep fluids down
• Very high blood glucose that does not improve according to your care plan

Planning for Work, School, Travel, and Caregiving

If you work, study, travel, or care for family members, preparation becomes even more important. Keep backup diabetes supplies in your bag, office, or car when temperature-safe. Make sure school nurses, workplace contacts, or caregivers know the basics of your plan. For travel, pack more medication and supplies than you expect to need, because luggage delays apparently enjoy dramatic timing.

People using insulin should protect it from extreme heat or freezing. Carry prescriptions, a medication list, and snacks. If you are traveling during flu season or a COVID-19 surge, consider masks in crowded indoor spaces, test before visiting high-risk relatives, and avoid travel when actively sick.

A Simple Diabetes, Flu, and COVID-19 Preparation Checklist

• Create a written sick-day plan with your diabetes care team.
• Keep extra diabetes medication and supplies available.
• Stock glucose testing supplies, ketone testing supplies, and a thermometer.
• Keep at-home COVID-19 tests and know where to get flu testing.
• Ask in advance whether you may qualify for flu or COVID-19 antivirals.
• Stay current on recommended vaccines.
• Store hydration options, easy foods, and rapid-acting carbohydrates.
• Know when to call your doctor and when to seek emergency help.
• Share the plan with someone who can help if you become very ill.

Real-Life Experience: What Preparation Looks Like at Home

Imagine a person named Mark who has type 2 diabetes and takes metformin, basal insulin, and a blood pressure medication. One Friday afternoon, he feels a scratchy throat and assumes it is just “office air,” which is what adults call germs when they are trying to sound optimistic. By evening, he has chills, a cough, and a glucose reading much higher than usual.

Because Mark prepared ahead, he does not have to improvise. His sick-day plan is taped inside a kitchen cabinet. It tells him to check glucose every four hours, drink fluids regularly, continue basal insulin, and call his clinic if readings stay above his agreed threshold. His kit has a thermometer, COVID-19 tests, glucose tablets, broth, electrolyte drink, and his medication list.

He tests for COVID-19 that night. The result is negative, but symptoms continue, so he repeats testing as directed. The next morning, he calls his clinic because he is at higher risk and still within the early treatment window. His clinician asks about symptoms, medications, kidney function, glucose numbers, and possible drug interactions. He gets guidance on whether testing for flu is needed and whether antiviral treatment is appropriate.

Now consider Lisa, who has type 1 diabetes and uses an insulin pump and CGM. She wakes up with fever and nausea. Her CGM shows rising glucose even though she barely ate breakfast. Because her care team reviewed sick-day rules with her, she checks ketones, changes her pump site when numbers do not respond as expected, sips fluids, and follows her correction plan. When ketones rise and vomiting continues, she calls urgently instead of waiting. That decision matters.

These examples show the main point: preparation reduces confusion. It does not make illness fun. Nobody catches flu and says, “Excellent, a chance to use my laminated checklist.” But a plan helps turn a scary situation into a series of manageable steps. Check glucose. Hydrate. Test. Call early. Watch ketones. Use treatment quickly if recommended. Rest. Protect others. Repeat.

Caregivers can also learn from this. If you help a parent, spouse, child, or roommate with diabetes, ask where supplies are kept and what warning signs require help. Learn how to use a glucose meter, where ketone strips are stored, and whether glucagon is prescribed. Write down the person’s medications, allergies, pharmacy, clinician’s number, and emergency contacts. When someone is feverish, weak, or confused, clear instructions are more useful than a heroic speech.

Another practical experience: many families discover during illness that their supplies are scattered everywhere. Test strips in one drawer, thermometer in another, expired COVID-19 tests in a closet, and soup cans hiding behind the holiday sprinkles. A monthly five-minute supply check can prevent this. Review expiration dates, refill prescriptions early when possible, replace used items, and keep the kit in one predictable place.

Finally, preparation includes emotional calm. Sick days can make people with diabetes feel frustrated or guilty when numbers rise despite careful choices. Remember: infection itself can raise glucose. The goal is not perfect numbers every hour. The goal is safety, hydration, timely treatment, and knowing when to get help. Diabetes management during flu or COVID-19 is not a character test. It is a medical plan, and plans work best when written before the plot twist.

Conclusion

Diabetes, flu, and COVID-19 are a serious combination, but preparation gives you a strong advantage. Start with a personalized sick-day plan, stay current on recommended vaccines, stock essential supplies, test early, monitor blood glucose more often, check ketones when advised, stay hydrated, and call your healthcare provider quickly when symptoms begin or numbers move into the danger zone.

Think of preparation as a seat belt. You hope you will not need it, but you are very glad it is there when life hits the brakes. With the right plan and support, people with diabetes can face flu and COVID-19 season with more confidence, fewer surprises, and a much smaller chance of turning a virus into a crisis.