Blood Glucose Monitoring and Control During Sickness?

When you get sick, your body faces many challenges. Fighting infection or injury puts stress on your system, which can affect your blood sugar levels.  For people with diabetes, understanding how illness changes blood glucose is very important. 

Illness can cause blood sugar to rise or fall unpredictably, making it harder to manage. This article explains why sickness affects blood glucose, how to check it properly during illness, and what steps you can take to stay safe and healthy.

How Illness Affects Blood Glucose

When you are sick, your body works hard to fight the illness. To do this, it releases stress hormones like cortisol and adrenaline. These hormones help your body respond to infections, but they also raise glucose levels.

Your body becomes more resistant to insulin, meaning insulin doesn’t work as well. This makes it harder for glucose to move from your blood into your cells. At the same time, your liver starts to release extra sugar into your bloodstream. As a result, your levels can rise, even if you’re eating less or not eating at all.

Reasons Why Illness Affects Blood Glucose

Here are some main reasons your blood glucose changes when you are sick:

• Stress hormones: Illness increases stress in the body. Hormones like cortisol raise blood glucose as part of your body’s natural defense system, showing how sugar affects your energy needs during sickness.
• Inflammation: Sickness causes inflammation, which can stop insulin from working properly. This leads to higher blood glucose levels, showing another way sugar affects your body when it’s inflamed.
• Not eating enough: If you’re not eating because of nausea, vomiting, or a sore throat, your blood glucose might drop, especially if you’re using insulin or other medications.
• Dehydration: Fever, vomiting, or diarrhea can lead to dehydration. This concentrates sugar in your blood and makes your glucose rise.
• Medications: Some common cold or flu medicines, like decongestants or steroids, may increase blood glucose levels.

Even a minor illness, like a cold, can make your blood glucose go higher than normal. For people with diabetes, this can be dangerous. High blood sugar for too long can lead to serious conditions such as diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS), which require urgent medical care.

What to Do Before You Check Your Blood Glucose

When you are sick, it’s important to check your blood glucose often and make sure your readings are accurate. Here are steps to follow before testing:

• Wash your hands: Clean, dry hands are important. Any sugar or dirt on your fingers can affect your reading.
  
• Check your meter and strips: Make sure your glucose meter is working well and your test strips are not expired.
  
• Prepare all your supplies: Get your meter, lancet device, test strips, and a way to record your results—like a notebook or app.
  
• Stay hydrated: Drink water regularly. Dehydration can give false readings or make it harder to control blood glucose.
  
• Avoid squeezing too hard: When getting a drop of blood, don’t squeeze too much. This can mix tissue fluid with blood and cause a wrong reading.
  
• Track symptoms: Write down how you’re feeling—nausea, fatigue, fever. This helps your doctor understand how illness affects your blood glucose.
  
• Be consistent: Try to test at the same times each day, such as before meals, two hours after meals, and before going to bed.
  

Accurate testing helps you and your healthcare provider make the right decisions during illness.

How Often Should You Check Blood Glucose When Sick?

When you’re sick, your blood glucose can change quickly. Even if you normally don’t check often, you should test more frequently when you’re unwell. Here’s how often to check:

• Every 4 hours: For most illnesses, check your levels at least every four hours even overnight if needed.
• Before and after meals: If you’re eating, test your levels before and about two hours after meals.
• If you’re not eating or vomiting: Check every 2–3 hours, as you may be at risk for low levels or ketones.
• Before bed and during the night: Make sure your levels are stable while you sleep. If needed, check during the night.
• Check for ketones: If your levels are above 240 mg/dL (13.3 mmol/L) or you are vomiting, use a urine or blood test to check for ketones. This is very important if you have diabetes.

If your readings stay high (above 300 mg/dL or 16.7 mmol/L) or go too low (below 70 mg/dL or 3.9 mmol/L), call your healthcare provider immediately.

Sick Day Tips to Help Manage Blood Glucose

Along with testing, you need to take care of your body in other ways. These simple tips can help you feel better and keep your blood glucose in control:

• Drink fluids often: Water and sugar-free drinks help remove excess sugar from your blood and prevent dehydration. Avoid sugary drinks unless your blood sugar is too low.
  
• Keep taking your medicine: Do not stop your insulin or other diabetes medicine unless your doctor tells you to, even if you’re not eating much.
  
• Eat small, simple meals: If you can’t eat full meals, try snacks like toast, soup, or crackers. Choose foods that are easy to digest but still provide some carbs to keep your blood glucose steady.
  
• Get plenty of rest: Your body needs extra energy to fight illness and heal.
  
• Have contact info ready: Keep your doctor’s number or your diabetes care team information somewhere easy to find.
  

Even if you are not hungry, try to eat a little every 3–4 hours to avoid dropping too low. Drink small sips of fluid often if you’re having trouble keeping things down.

When to Get Medical Help

Sometimes being sick at home isn’t enough. Know when to get help. Call your doctor or go to the hospital if:

• You have high blood glucose and positive ketone results
  
• You are vomiting or have diarrhea for more than 6 hours
  
• You feel very weak, sleepy, or confused
  
• You can’t keep food or liquids down
  
• You have trouble breathing or feel chest pain
  

Waiting too long can make the situation worse. Always get help if you feel unsure or your symptoms are getting stronger.

Conclusion

Being sick affects your body in many ways. It can make it hard to keep your blood glucose at a safe level. Stress, inflammation, lack of food, dehydration, and medications all play a role. For people with diabetes or anyone who monitors their sugar, being sick means extra care is needed.

Here’s what to remember:

• Test your blood glucose more often.
  
• Follow steps to make sure your tests are accurate.
  
• Stay hydrated and eat when you can.
  
• Don’t stop your medicine without asking a doctor.
  
• Know when to get medical help.