It's important to know how to manage your diabetes when you're ill.
Some people will know this as diabetes sick day rules.
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 along with diet.
This is really important if you go into hospital or if you need to take steroids as part of your treatment.
Always tell the healthcare professionals treating you that you have diabetes and how you manage and monitor it.
How illness affects diabetes
Illness and infections, as well as other forms of stress, can raise your blood glucose (sugar) levels 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 off your food or eating less than usual.
People who don’t have diabetes just produce more insulin to cope. 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.
Feeling or being sick, or having diarrhoea can make your blood sugar levels drop, because you're not absorbing food as usual.
Being dehydrated when you have diabetes
Having a temperature or being sick can lead to dehydration. In some cases, severe dehydration and very high blood sugar levels can mean that you need to go into hospital.
So it’s important to be prepared and follow our advice on coping 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 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. But there are some medicines that you shouldn’t take as much of or you should stop taking altogether. 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.
- Insulin may need to be increased or decreased when you're unwell, talk to your diabetes team for further advice on how to manage your insulin doses during illness.
- If you check your blood sugars at home you'll probably need to do it more often – 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 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. But they may have given you different targets. Regardless of what your blood sugars are saying, if you're sick, test for ketones and If you find them, contact your healthcare team.
- If you take a certain type of diabetes tablet called SGLT2i and become unwell, you should 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 SGLT2i 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. Try snacks or drinks with carbohydrates in to give you energy. Try to sip sugary drinks like fruit juice or non-diet coke or lemonade or suck on glucose tablets or sweets like jelly beans. If you are being sick letting fizzy drinks go flat may help 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, lupus and coronavirus are treated with steroids. 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.
Some people with coronavirus are treated with a type of steroid called dexamethasone. Not everyone with coronavirus will need this steroid – it’s used in hospital or in virtual wards when someone is really unwell and needs help to breathe. Some people may be treated with dexamethasone at home. It works by reducing the inflammation that coronavirus can cause and supports your immune system to fight it.
While this works well for treating coronavirus, the side effects can affect blood sugars. Dexamethasone makes your body more resistant to insulin and raises blood sugar levels. If you already take insulin you should speak to your healthcare team who will advise on any changes to insulin doses that may be required to help reduce your blood sugar levels.
If you don’t have diabetes and are prescribed steroids, it’s important to know that taking this medication could cause diabetes to develop later on. This is called steroid-induced diabetes. We've got more information about the condition, including the symptoms to look out for. You can also 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 and covid booster 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.