Insulin During Illness: What You Need to Know When You're Sick

When you're sick, your body releases stress hormones like cortisol and adrenaline that make your liver pump out more glucose — even if you're not eating. For people with diabetes, this means insulin during illness isn't optional, it's essential. Insulin, a hormone that helps your cells absorb sugar from the blood. Also known as blood sugar regulator, it's the lifeline for people with type 1 diabetes and many with type 2 who need it to survive. Skipping insulin because you're nauseous or not eating can lead to diabetic ketoacidosis, a life-threatening condition that lands people in the hospital.

Illness doesn't just raise blood sugar — it also makes your body use insulin differently. Infections, fever, or even a bad cold can increase insulin resistance. That’s why checking your blood sugar every 2 to 4 hours is non-negotiable. You might need more insulin than usual, even if you're eating less. Some people think, "I didn't eat, so I don't need my insulin," but that’s a dangerous myth. Your body is still burning fuel, and without insulin, it starts breaking down fat for energy, which produces toxic ketones. Diabetic ketoacidosis, a buildup of acidic ketones in the blood due to severe insulin shortage is the silent threat here. And blood sugar control, the ongoing effort to keep glucose levels within a safe range becomes harder when you're vomiting, dehydrated, or on steroids for another condition.

Knowing what to do when you're sick isn't about guessing. It's about having a plan. Most diabetes educators recommend a "sick day rules" checklist: keep drinking water, test blood sugar and ketones if possible, never skip basal insulin, and adjust rapid-acting insulin based on readings — not appetite. If your blood sugar stays above 240 mg/dL for two checks in a row, or if you have moderate to large ketones, call your doctor. Don't wait. Many people delay because they think it's "just a cold," but diabetes doesn't take days off. The posts below give you real, no-fluff advice from people who’ve been there — how to adjust insulin doses during flu season, what to do when you can't eat, how to tell if you need emergency care, and why some over-the-counter meds can mess with your numbers. You'll find practical tips that actually work, not theory. This isn't about being perfect. It's about staying safe when your body is under stress.