Diabetes management when people living with Type 1 Diabetes are sick


October 4th, 2022

Diabetes management when people living with Type 1 Diabetes are sick

1. How does illness affect blood glucose levels?

Those with diabetes can get sick once in a while, just like anyone else. However, because the effects of illness on the body can raise or lower blood glucose levels, a few extra steps are needed to keep blood glucose levels under control.
Blood glucose levels can be very unpredictable on sick days. You can’t know exactly how the illness will affect diabetes control. So, when those with diabetes are sick, it’s important to check their blood glucose levels more often than normal and adjust insulin doses as needed.
If a person with diabetes is sick with the cold, flu or any other illness, with or without a fever, the body needs extra energy to fight off the germs. And it might interfere with the action of the insulin.
The cells may need more or less insulin to work. Eating, drinking, monitoring blood glucose levels and taking insulin are all extremely important when a diabetic person is ill.
If the cells do not get enough energy, or if there isn’t enough insulin to help the glucose get into the cells, the body breaks down its own stores (fat and muscle) to provide this energy. This process produces waste products called ketones, which are dangerous in high quantities.
If high blood glucose levels are not treated, ketones will develop and the diabetic may become sick with diabetic ketoacidosis (DKA) even without an identifiable illness.

2. How can I be prepared for sick days?

Knowing how to manage sick days should prevent any major problems and complications.
The goals of sick day care are to:

  • Prevent dehydration
  • Prevent ketoacidosis (high levels of sugar and ketones in the blood)
  • Prevent hypoglycaemia (low blood glucose levels).

3. How to recognize ketones?

Here are some symptoms to recognize when blood ketones are being produced by the body:

  • Breath that smells fruity
  • High blood glucose levels
  • Going to the toilet a lot
  • Being really thirsty
  • Feeling more tired than usual
  • Stomach pain
  • Changes to their breathing (usually deeper)
  • Confusion
  • Fainting
  • Feeling or being sick

The best way to test ketones is by using blood ketone test strips. Many people do not have blood ketone test strips and the machine available at home. Your local clinic or healthcare centre may be able to do this.

4. What should I do when someone with Type 1 Diabetes is sick?

Please follow these general guidelines during any illness:

  • Insulin dose may need to be increased or decreased, based on blood glucose level and food intake
  • Increase blood glucose monitoring to 3-4 hourly if test strips available
  • If unable to test blood glucose levels at home, admit to a local health facility for regular testing
  • Ensure adequate fluid intake
    Example fluid suitable for children during sick day: Plain water, soup broth . Encourage them to drink small amounts of liquid (about a 1/2 cup every hour). Avoid caffeinated beverages which could cause dehydration such as sodas, tea and coffee.
  • Treat fever.
  • Encourage to eat normal main meals, but if unable to eat, make sure he or she is taking in a certain amount of liquid or solid carbohydrates to prevent sudden drops in blood glucose.

Monitoring for urinary or blood ketones is very important. Additional insulin is usually necessary to control blood glucose levels (unless the illness causes hypoglycaemia).
“In case of elevated blood glucose level with no or small ketones:
-> Give 5-10% of total daily dose of insulin as short or rapid-acting insulin and repeat every 2-4 hours.”

“In case of elevated blood glucose level with moderate or large ketones:
-> Give 10-20% of total daily dose of insulin as short or rapid-acting insulin and repeat every 2-4 hours.”

If the person is vomiting, this is a sign of insulin deficiency and diabetic ketoacidosis (DKA). Please call your doctor immediately or go to the local clinic/hospital.


HelloType1 content is based on published, internationally recognised guidelines and then reviewed by local experts to ensure it fits local context. The translation is based on simplified English language to ensure it conveys the safest and clearest possible message in regional languages. Basic insulin and blood glucose testing access is still an issue in the South-East Asia region and our chief aim is to address this. HelloType1 content is not intended to replace the advice of individual healthcare professionals but as a collaborative tool to help them improve the outcomes of disadvantaged people with Type 1 Diabetes in the region.

HelloType1 content is curated for the topics using information only taken from accredited sources such as the International Diabetes Foundation (IDF) and the International Society for Paediatric and Adolescent Diabetes (ISPAD).

This content is then reviewed and adapted by a panel consisting of healthcare experts (e.g. endocrinologist, nutritionist, diabetes nurse, psychologist) and members of the South-East Asia T1D communities, helping ensure the information is appropriate in a local context.

Writers of HelloType1 content:
Anne-Charlotte Ficheroulle, Pharmacist, Digital Innovation Manager at A4D
Charlotte O’Brian Gore, Research assistant ImmunoEngineering, King’s College. UK

Content Reviewers – healthcare professionals:
Dr. May Ng, Paediatric Endocrinologist, Chief Medical Advisor A4D, UK
Dr. Yeow Toh Peng, Endocrinologist, Malaysia
Dr Jaturat Petchkul, Paediatric Endocrinologist, Thailand
Dianna Culbertson, Physician Assistant T1D care, US
Prof Dr Malene Iv, Endocrinologist, Kantha Bopha Hospital, Cambodia
Steffen Tange, Consultant Psychology, Denmark
Soe Nyi Nyi, Nutritionist, Myanmar
Lucas Lim, Dietician, Malaysia

Content Reviewers – people with Type 1 Diabetes:
Jerry Gore, Co-Founder A4D, Mountaineer, UK
Diana Maynard, T1D advocate, UK
Emelyne Carmen Ho, College Student, Malaysia
Molly Seal, College Student, UK

Content Reviewers – parents with T1D child:
Samantha Seal, Teacher, Thailand
Kim Than, Deputy Country Director – Plan International, Cambodia

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