Sick Day Management with Type 1 Diabetes
Friday, November 27, 2020

Illness can strike at any time, so it is important that you discuss with your Diabetes team how best to manage your diabetes when ill, so you are prepared in the event of any illness. Have written instructions for ‘sick day rules’ from your diabetes team so you can refer to them when needed.


When the body is fighting illness, it can cause blood glucose levels to rise. This is due to the body’s defence mechanism for fighting illness and infection which causes more glucose to be released into the bloodstream. This happens even when you are eating less than usual. Therefore, when ill it is essential to manage your blood glucose levels as well as the illness.

When blood glucose levels are high, and there isn’t enough insulin in the body to allow glucose to move from the blood into the cells where it is needed to make energy the body starts to break down fat as an alternative fuel. This process leads to the build-up of ketones in the blood. When too many ketones are produced too quickly it can cause the blood to become acidic, which can lead to illness and Diabetic Ketoacidosis (DKA) a serious life-threatening complication of Type 1 diabetes.

Symptoms of Diabetic Ketoacidosis 

The symptoms of Diabetic Ketoacidosis include:

  • Thirst
  • Passing urine excessively
  • Feeling very unwell
  • Nausea or vomiting
  • Tiredness and confusion
  • Difficulty breathing
  • Stomach pain
  • Breath smelling of pear drops or nail polish remover

A person with Type 1 diabetes is at risk of DKA when ill. To prevent DKA, follow the sick day advice outlined by your diabetes team. If you have high blood glucose levels and signs of DKA seek medical advice immediately or go to the nearest emergency department for treatment.

Be aware of the warning signs of Diabetic Ketoacidosis and know when to seek emergency care. Your diabetes team may give you more specific sick day advice, so it is important to discuss it at your appointments so you will have a plan in the event of you becoming unwell, to prevent a minor illness becoming a major problem. If in doubt about what to do seek advice from your diabetes team and know who to contact out of hours.

General Guidelines for the management of Type 1 diabetes during illness:

■ Check your glucose level every 2-4 hours (even during the night) and adjust your insulin/food intake accordingly as per the advice from your diabetes team

■ Eat normally if you can and keep hydrated by sipping on water and sugar free fluids

■ If you are unable to take solid food, take carbohydrate in fluid form e.g. flat soft drink (not diet variety), sip on this to maintain your blood glucose levels

■ If you think you may have an infection or other illness that is causing the high blood glucose levels you should visit your G.P.

■ If you are using an insulin pump you may be at a greater risk of DKA when ill or if your pump has technical problems affecting insulin delivery. It is essential that you are familiar with how to manage high blood glucose levels when on an insulin pump to avoid the risk of DKA. Keep a supply of insulin pens in the fridge in case you need to go back to injections if your insulin pump fails. Your diabetes team can advise you on this.

Checking for Ketones

If you feel unwell or your blood glucose levels are high (greater than 14mmols/L) you should check for blood ketones using certain blood glucose meters and blood ketone testing strips which are available on prescription. Your diabetes team should instruct you how to test for ketones and what to do if ketones are detected. Illness can strike at any time so it is important to ensure that you always have a supply of blood ketone testing strips that are in date should you need them.

Information from Diabetes Ireland

Diabetes Ireland