How Do I Maintain My Blood Sugar When I Cannot Eat Due to Illness?

I Cannot Eat Due to Illness?

Diabetes doesn’t take a time off. Even if you are sick, you will still need to manage your metabolic condition. Everyone responds differently when they are sick. Typically, people adjust their bolus to accommodate their high blood sugar levels. 

Even if you don’t eat, your body continues to make glucose. During this time, it is critical to keep an eye out for your glucose levels and consult with a doctor. After a while, you can learn how your body responds to different illnesses, such as cold, diarrhea, headaches, stomach flu, etc. 

Here, you can find some general guidelines on what are the sick day rules for diabetics.

Can being sick affect your blood sugar levels?

A rise in blood sugar level is very common when sick. It doesn’t always happen, but it can occur. Hyperglycemia (high blood sugar) in diabetes is thought to trigger dysfunction of the immune response. So, the body can’t control the spread of invading pathogens.  

When you are sick, or you are under a lot of stress, your blood sugar can be off the charts. This is a natural defense mechanism. Insulin resistance can increase, thus releasing lots of different hormones, which can force the liver to release glucose. 

You might not be able to eat or drink food as you normally do. This can make it harder to control glucose levels. 

How can I keep my blood sugar stable when sick?

Keep taking your insulin even if you can’t eat too much. Most patients need to augment their basal and boluses by the same amount. Others may need to double it. Since diabetes is different for everyone, you must consult with a healthcare professional first.

If you can’t eat a regular meal, then you should consume (or drink) roughly 50g of carbs every 4 hours. People who can’t keep their food down should get carbohydrate-rich drinks. For example, 1½ cup of fruit juice or 1½ cup of applesauce (unsweetened).

Other foods to eat when sick are:

  • Crackers
  • Canned soup
  • Dry toast
  • Sports drinks
  • Regular pudding
  • Instant cooked cereal
  • Hard candy

Don’t forget to drink lots of fluids. When you are sick, vomiting, or have diarrhea, you are more likely to get dehydrated. Replenishing the fluid intake helps the blood sugar and prevents dehydration. Drink 4 to 6 ounces every 30 min. 

Fluids you can drink when the glucose is low are:

  • Grapefruit juice
  • Orange juice
  • Tea with honey
  • Ginger ale
  • Lemon-lime drink

Can you cut the carbs with diabetes when sick? 

Cutting the carbs completely from your diet when sick is not a good idea. The body is fighting off an illness that requires all sorts of resources. So, you have to replenish your energy sources and nutrient intake. 

If you have an upset stomach, try to eat smaller portions and opt for carbohydrates such as mashed potatoes, bagels, bread, noodle soup, or graham crackers. Remember, on your sick day, it is OK to consume foods that you wouldn’t normally eat.

Double check the food label to see if the food you like has the necessary carb content. If you can’t swallow or your throat hurts, opt for softer foods. These include soups, broths, mashed potatoes, etc. Don’t skip your diabetes medicine even when you are sick. If the vomiting persists, call your doctor. 

How to control diabetes when sick and not home? 

Anyone can get sick when they are away from home. For a diabetic patient, it is critical to let your friends, professors, and colleagues know about the signs of low or high blood sugar. In the meantime, take your medicine and check your glucose more often. 

Keep a couple of snacks nearby or carry them in your bag or purse. These can help you mitigate blood sugar fluctuations and give the body some energy. Keep your diabetes identification card or tag on you constantly. 

If you have to drive for a while, check your blood sugar before you get behind the wheel. Stop driving every 2 hours and check the glucose again, just to make sure it is within the target range. If you are feeling dizzy, and can’t concentrate, don’t drive. Have someone else drive you or see a doctor.

In case you are leaving the house for a vacation or a long trip, bring twice as much diabetes medicine and supplies as you normally need. Including a first aid kit. This way, you make sure that you get the necessary amount of medicine no matter what happens.

The supplies and medicine you need are:

  • Suppositories for treating vomiting
  • Thermometer
  • Pain reliever
  • Medicine for diarrhea
  • Antacid
  • Milk of magnesia

Other tips for sick days with diabetes

  • Don’t panic. Consult with your diabetes healthcare team if you are having trouble keeping the condition under control. 
  • Don’t stop taking your diabetes medicine. Even if you don’t feel like eating anything, your body still needs diabetes medicine. So, keep taking your diabetes meds and insulin as usual or as your doctor recommended. 
  • If you are taking steroids, talk to your doctor. Certain health issues such as the coronavirus, hives, painful joints, and severe asthma require steroid treatment. If you are diabetic and are taking high steroid doses, the glucose can increase. Your doctor might suggest you make a couple of changes as a safeguard for your glucose levels. 
  • Test the glucose every 2 to 4 hours (type 1 diabetes) or 4 to 12 hours (type 2 diabetes). Illnesses can be unpredictable. You need regular monitoring to make sure the body is stable.
  • Check the blood ketones. If you have nausea or vomiting, the ketone levels can skyrocket. If your blood ketones are too high, get expert help. 


Keep a close eye on your diabetes when sick. Even if you can’t eat, you should drink about 50g of carbs every 4 hours. Depending on your health state, you may have to alter the insulin doses. But do not adjust your bolus or any diabetes medicine without consulting a doctor first. If you can’t take care of yourself, see a specialist.