Managing your diabetes when you are unwell is important. An ‘everyday illness’ can affect your blood glucose levels, making it more difficult to manage your diabetes.

A ‘sick day’ – when you have an illness or an infection – means you’ll need to make changes to your usual diabetes management regime to keep your blood glucose levels in the target range.

What happens when you are sick?

When you’re sick, your body releases stress hormones to help you fight the infection or illness.

The stress hormones can cause your liver to release glucose into your blood. They can also make it harder for insulin work effectively.

This can cause a rise in blood glucose levels.

People who do not have diabetes are able to keep their blood glucose levels in a normal range as their body releases more insulin when they are sick.

Everyday illness & type 1 diabetes 

Even a minor illness can lead to a major rise in blood glucose levels.

This will increase the amount of insulin you need to keep blood glucose levels within your target range.

If the blood glucose levels remain high for several hours the body will start to produce ketones.

Ketones are toxic, and if they build up to moderate to high levels, diabetic ketoacidosis (DKA) can develop. This is a life-threatening condition.

Your healthcare team can provide you with a sick day action plan that you need to put in place when you become ill.

Careful monitoring of blood glucose and ketone levels and adjusting your insulin will form part of your plan.

You need to put your plan into action if:

  • You are unwell or have any signs of illness, even if your blood glucose levels are normal.
  • Your blood glucose levels are greater than 15mmol/L for 6 hours or more, even if you feel well.
  • You have ketones in your blood or urine.

Diabetic ketoacidosis (DKA) is a very serious condition and requires urgent medical attention.

Symptoms of DKA may include:

  • Nausea and vomiting
  • Abdominal pain
  • Increased thirst or dry mouth
  • Reduced or no urine output
  • ‘Fruity’ smelling breath
  • Difficulty breathing
  • Drowsiness or coma

Fact sheet: Managing sick days for type 1 diabetes

Everyday illness & type 2 diabetes

Managing everyday illness when you have type 2 diabetes is important.

Any illness can cause a rise in your blood glucose levels and put you at risk of dehydration.

Severe dehydration can lead to you feeling drowsy and confused. Severe dehydration requires urgent medical attention.

You and your diabetes healthcare team can work together to develop a sick day action plan before you become ill to make it easier to take care of your diabetes when you are not feeling well.

Put your plan into action if you feel unwell or have any signs of illness.

If you self monitor your blood glucose levels and they are higher than 15mmol/L for 8-12 hours or more, start following your sick day plan even if you feel well.

Sometimes people who manage their diabetes with diet or oral medicine alone, need insulin to help keep their blood glucose levels in a target range until they are well again.

Your doctor will advise you if you need to start or change medicine or insulin.

Important: Do not take more insulin or medicine without your diabetes nurse educator or doctor’s advice.

Fact sheet: Managing sick days for type 2 diabetes

What is a sick day action plan?

A sick day plan is step-by-step written instructions on how to manage your diabetes when you are unwell.

A sick day plan is tailored to you as an individual, and it should be reviewed every 1 to 2 years.

Information in a sick day action plan includes:

  • A target range for your blood glucose level
  • When to check your blood glucose levels – and how often
  • When and how to make changes to your medication (including insulin)
  • How often and how much to drink to avoid becoming dehydrated
  • When to seek medical help

Be prepared before you get sick – have a personalised sick day action plan and sick day management kit ready to use.

What are the signs of illness?

Typically signs of illness can include:

  • Nausea or vomiting
  • Diarrhoea
  • Shaking chills or fever
  • Muscle or joint aches
  • A strong to severe headache
  • Stomach cramps