It's important to know how to manage your diabetes when you're ill.
Some people will know this as diabetes sick day rules.
On this page:
- How illness affects diabetes
- Your sick day rules - how to manage diabetes when you're sick
- If you're taking steroids
- Protecting yourself against illness
How illness affects diabetes
Illness and infections, as well as other forms of stress, can raise your blood glucose (sugar) to dangerously high levels.
As part of the body’s defence mechanism for fighting illness and infection, more glucose is released into the blood stream. This can happen even if you’re eating less food than usual.
People who don’t have diabetes produce more insulin to cope when they're ill. But when you’ve got diabetes, your body can’t do this. The symptoms of having diabetes can add to those of your illness or infection and make it much worse.
Having high blood sugars can give you symptoms such as needing to go to the toilet for a wee a lot more often or feeling very thirsty or tired. These can add to the symptoms of your illness or infection and make you feel worse. The symptoms of your illness can also affect your diabetes.
If you are feeling or being sick, or having diarrhoea then this can make your blood sugar levels drop, because you're not eating or absorbing as much food as you usually would.
If you have a temperature or you’re being sick then this can lead to dehydration. In some cases, severe dehydration and very high blood sugar levels can mean that you need to go into hospital.
When you’re ill, you'll need to know how to manage your insulin doses and other diabetes medications, as well as monitoring your blood glucose (sugar) and ketone levels. If you have to go into hospital for your illness, its important that you tell the doctors and nurse about any changes to your insulin doses or other medications. Always tell the healthcare professionals treating you that you have diabetes and how you manage and monitor it.
So it’s important to be prepared when you’re poorly, so use our ‘sick day rules’ advice below to help you cope when you’re sick. You might want to give this information to a friend or family member, so they can help you if you get become unwell.
Your sick day rules - how to manage diabetes when you're sick
- Don't panic – contact your diabetes team who will help you if you have any queries or if you are unsure about what to do.
- Keep taking your diabetes medications – even if you don't feel like eating. However there are some medicines, such as SGLT2 inhibitors, that you might need to take at a lower dose or stop taking altogether when you're poorly. Make sure you talk to your diabetes team or speak to a local pharmacist as soon as you’re feeling ill so they can give you the right advice.
- You may need to increase or sometimes decrease your insulin levels when you're unwell, but make sure you talk to your diabetes team for further advice on how to manage your insulin doses during illness, if you haven't already been given guidance on this.
- If you check your blood sugars at home you'll probably need to check them more often, either on your continuous glucose monitor (CGM) or your blood glucose meter – at least every four hours, or as advised by your healthcare team, including during the night. If you don't test your blood sugars at home, be aware of the signs of a hyper (hyperglycaemia).
- Stay hydrated – have plenty of unsweetened drinks and if you're struggling to eat your food, eat little and often.
- If you have type 1 diabetes, it’s important to check ketone levels if your blood sugar levels are above your target range (usually above 14mmmol/l) and as advised by your healthcare team. You may also be advised to do this in you have another type of diabetes. Regardless of what your blood sugar level is, if you're sick, test for ketones and If you find them, contact your healthcare team.
- If you take SGLT2 inhibitors and become unwell with an illness or infection you should temporarily stop taking these.You need to check your ketones and your blood sugars (if you've been told to do this and have the kit), and speak to your healthcare team. There are different types of SGLT2 inhibitor tablets so check our list for all the brand names. Taking these tablets when you're not very well could increase your risk of developing diabetic ketoacidosis (DKA), so you need to know the symptoms to look out for.
- Keep eating or drinking – if you can’t keep food down try eating little and often. The important thing is to keep up your carbohydrate intake, so try snacks or drinks with carbohydrates in to give you energy. If you are being sick, letting fizzy drinks go flat may help you to keep them down. If you're still not able to keep any fluids down get medical help as soon as possible.
If you're taking steroids
Some conditions, like Addison's disease, severe asthma, rheumatoid arthritis, and lupus are managed with steroids. When you become unwell and have these conditions the doses of steroids are often increased. Steroids are also used in the treatment of many illnesses.
If you have diabetes, taking high doses of steroids for periods of time can make your blood sugar levels rise. This is called steroid-induced hyperglycaemia. Your doctor or nurse will talk to you about this. They may ask you to make some changes to how you manage your diabetes, so that you can keep your blood sugar levels within your target range.
If you don’t have diabetes and are prescribed steroids, it’s important to know that taking this medication could cause diabetes to develop. This is called steroid-induced diabetes. You can speak to your healthcare team for more guidance and advice.
Protecting yourself against illness
There are things you can do to protect yourself against some illnesses.
This includes getting your flu jab every year. And it may sound simple, but avoiding people who are sick and washing your hands often and thoroughly can help to protect yourself and others too.
