by Stahl RJ

IMAGE Whether you have a head cold or the flu, being sick can put all of your activities on hold. You are forced to stop and take care of yourself. But, if you have type 1 or type 2 diabetes, this demands extra attention.

When you are sick, you are more likely to have a high blood sugar (glucose) level also known as hyperglycemia. This happens because your body creates more hormones to fight infection, and these hormones can counteract the effects of insulin. If insulin cannot do its job, then glucose builds up in the blood.

Test Your Blood Sugar Often

Since being sick puts you at risk for hyperglycemia, you should consider checking your blood glucose more often. You may need to test more often than usual.

What is considered high? This depends on your target range. According to the American Diabetes Association, you should aim for tight control, keeping glucose levels as close to normal as possible (80-130 milligrams per deciliter [mg/dL] before a meal, less than 180 mg/dL 1-2 hours after starting a meal). But not everyone is able to achieve this. Ask your doctor what levels are right for you and when you should call for additional medical advice.

You also need to know how to adjust your medication to treat high glucose levels. Ask about the amount of insulin you should give yourself to bring the levels down. If you take oral diabetes medication, find out how to adjust the dose. If you do not already have this information, work with your doctor to create a sick day plan so that you will be prepared.

In addition to testing your blood glucose levels, be alert for the symptoms of hyperglycemia such as having to urinate frequently, being very thirsty, and having blurry vision.

Test for Ketoacidosis

If you have diabetes and high glucose levels, you are at risk for a dangerous condition called diabetic ketoacidosis (DKA), especially if you have type 1 diabetes. DKA happens because the body does not have enough insulin, and your body cannot use glucose for fuel. Instead, your body uses protein and fats for fuel. This leads to a build up of a by-product called ketones. When they build up they can make you seriously ill.

Symptoms usually begin with very dry mouth and frequent urination. Later, you may experience fatigue, dry or flushed skin, nausea and vomiting, abdominal pain, difficulty breathing, fruity odor on breath, and confusion. If you have any of these symptoms, call for emergency medical services right away.

Ketone levels can be checked with urine tests that are sold at drug stores. Ask your doctor whether you should check for ketones while you are sick and when you should test (such as a blood glucose level over 240 mg/dL). Call the doctor if the results show moderate to large amounts of ketones.

Stick to Your Routine

When you are feeling nauseous or vomiting, the last thing you want to do is eat. But when you have diabetes, it is important to stick to your regular meal plan as much as possible. Your body needs the same amount of carbohydrates that it’s accustomed to.

So how do you do this? Ask your doctor or dietitian how to make food exchanges so you get the nutrients that you need. For example, try eating broth-based soups, saltine crackers, and frozen fruit bars. If you have had vomiting or diarrhea, replenish the lost fluids.

Remember to continue taking your insulin even if you are not eating your regular diet. However, your dose of insulin may need to be adjusted. Call your doctor if you have severe vomiting or diarrhea or your eating pattern has changed a lot.

Insulin without adequate food intake while you are sick may lead to low blood glucose (hypoglycemia). Some of the symptoms of having a low glucose include shakiness, lightheadedness, headache, sweating, and hunger. When your glucose levels fall below 70 mg/dL you may drink soft drinks (with sugar), juice, and sports drinks (with sugar and carbs). They should help your glucose rise quickly.

Take Your Temperature and Carefully Choose Cold Medicines

Keep a thermometer on hand. If your temperature is over 101°F (38°C), call the doctor.

Read the labels carefully on all cold medicines. Some contain ingredients that can affect your blood glucose. For example, pseudoephedrine in decongestants can raise your blood glucose level. Other cold medicines have sugar or alcohol. These are usually safe when taken as directed. To be safe, you may want to opt for medications that are sugar-free and alcohol-free.

If you also have kidney disease, avoid all products that contain ibuprofen or other nonsteroidal anti-inflammatory drugs (NSAIDs). These medications can cause kidney failure. Talk to your doctor about which over-the-counter drugs might be safe for you.

Monitor Your Cold

Keep close tabs on your cold. If a couple of days have passed and you don't feel better, call the doctor. Provide details about your illness such as when you got sick, what your symptoms are, what you have been eating and drinking, what your glucose and ketone levels are, and any other important facts. If you have fatigue, stomach or chest pain, or breathing difficulty, call the doctor right away.

Get Your Shots

Avoid the flu by getting the flu shot once a year. They are typically offered starting in the fall. One shot per year is all that is needed to protect you from this life-threatening infection. If you have never been vaccinated against pneumonia, ask your doctor.

Make Your Sick Day Plan

If you have not already made a sick day plan with your doctor, schedule an appointment to discuss:

  • What blood glucose levels are considered high for you and when you should call the doctor
  • How to adjust your medication to bring the blood glucose level back into the normal range
  • How often you should test for ketones and when you should call the doctor
  • What food exchanges you can make if you are not feeling well enough to eat your regular diet
  • Which cold remedies may be safe for you
  • Whether you have had your flu and pneumonia shots

Being prepared can go a long way to help you to cope with your illness and to avoid serious health problems.


American Diabetes Association 

National Diabetes Information Clearinghouse 


Canadian Diabetes Association 

Public Health Agency of Canada 


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Diabetes mellitus type 1. EBSCO DynaMed Plus website. Available at: . Updated August 29, 2016. Accessed October 13, 2016.

Diabetes mellitus type 2 in adults. EBSCO DynaMed Plus website. Available at: . Updated August 29, 2016. Accessed October 13, 2016.

Diabetic ketoacidosis (DKA) in adults. EBSCO DynaMed Plus website. Available at: . Updated May 6, 2016. Accessed October 13, 2016.

Take charge of your diabetes. Center for Disease Control and Prevention website. Available at: Accessed October 13, 2016.

Taking care of your diabetes at special times or events. National Diabetes Information Clearinghouse website. Available at: Updated February 2014. Accessed October 13, 2016.

Tight diabetes control. American Diabetes Association website. Available at: Updated May 13, 2015. Accessed October 13, 2016.

When you're sick. American Diabetes Association website. Available at: Updated June 5, 2015. Accessed October 13, 2016.

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