
Managing insulin when you are sick
If you are ill, need surgery, or go through a period of severe emotional stress, you may need to change your normal diabetes routine.
When you are unwell your body releases hormones that increase your blood glucose (sugar) levels. You may need more insulin, even though you may not be eating as much as usual, or even vomiting. This is why we manage diabetes differently when you are sick, to stop you from developing high blood sugar levels.
If you have type 1 diabetes, you also need to avoid developing diabetic ketoacidosis (which is often called DKA).
If you are unwell:
- avoid hypoglycaemia (low blood sugar)
- avoid becoming dehydrated
- make sure you still eat well (good nutrition)
- follow the advice below to prevent DKA if you have type 1 diabetes
- know when to ask for help.
See your doctor urgently if:
- you are vomiting a lot or constantly
- you can't keep your blood sugar levels above 4 mmol/l
- your blood sugar levels remain high
- you have type 1 diabetes and your blood sugar levels remain above 15 mmol/l after two extra doses of rapid-acting insulin (if you have been prescribed it), or if ketones are increasing or stay high
- you get worse or develop new symptoms.
Guidelines for managing sick days
- Relieve your symptoms: take paracetamol regularly to reduce your fever and relieve any headaches or other discomfort. Talk to your GP about other medication for any specific illness.
- Continue to use insulin. You may need to adjust the dose but don't stop having your usual injections.
- Test your blood sugar every two hours. If your blood sugar levels are less than 4 mmol/l, test every hour.
- If you have type 1 diabetes and use a ketone meter, measure your ketones if you blood glucose is persistently above 15 mmol/l.
- Drink enough fluid – about a glass every hour.
- For type 1 diabetes if your blood sugar levels are below 15 mmol/l and you are not eating, drink sweetened fluids such as soft drink, lemonade ice-blocks, ordinary jelly, and fruit juice. If your blood glucose levels are above 15 mmol/l drink unsweetened fluids.
- For type 2 diabetes, if your blood sugar levels are below 8 mmol/l and you are not eating, drink sweetened fluids such as soft drink, lemonade ice-blocks, ordinary jelly, and fruit juice. If your blood glucose levels are above 8 mmol/l drink unsweetened fluids.
- Keep good records – write down the results when you test your blood sugar.
- Avoid strenuous exercise, especially if testing shows ketones are present.
Surgery and fasting
If you have to fast before having surgery or a medical procedure, make sure you have guidelines for adjusting your insulin beforehand. Speak to your GP about this.
Who to call
If you have questions during office hours, call your GP or practice nurse. If you have questions outside office hours, call your GP or an after-hours GP service.
Replacing fluid
You can take rehydration solutions, such as Gastrolyte, to replace fluid and electrolytes lost through diarrhoea or dehydration. However, rehydration solutions have relatively low concentrations of carbohydrates, so you may need extra carbohydrates.
Take care with sweetened fluids if you get diarrhoea. You may have to dilute them up to five times so you can absorb them well.
Written by nursing staff at the Diabetes Centre, Christchurch.Adapted by HealthInfo clinical advisers. Endorsed by clinical director, Diabetes Services, Canterbury DHB. Last reviewed November 2016.
Sources
The information in this section comes from the following sources, some of which may be clinically complex or not available to the general public.
Australian Diabetes Education Association. (2006). Guidelines for sick day management for people with diabetes.
Hanas, R. (2005). Type 1 diabetes. A guideline for children, adolescents, young adults – and their caregivers. (pp 27-30,99-101,258-63). New York: Marlowe & Company.
Harris, G., Bluck, E., Whitney, S. (Eds.). (2002). Caring for diabetes in children and adolescents. A parents' manual. New Zealand Edition. (2nd ed.,pp. 62-69. 81-82, 84-90). New Zealand: Brebner Printing.
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