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Illness, Sick Day Rules and Diabetes

When you have diabetes and are feeling unwell there are steps you should follow to avoid your diabetes getting out of control or needing hospital treatment.

What happens to my blood sugar during illness?

People often worry that their blood sugar will go low but, because of the stress of an illness or infection, it can rise even if your are not eating as normal. That’s why it is important never to stop taking your insulin or tablets when you are ill because the blood tests may rise even higher. In fact, this often means you may need to increase your insulin dose.

What should I do if I am unwell?

When you are unwell, you need to know if your blood test is staying under control. Usually you blood tests should run below 7 before eating and below 11 at other times. If you are unwell and they rise more than that then something needs to be done about it. If they are above 20 that is very high and you must take action as well as seeking advice and help.
Test your blood sugar more frequently than usual, about every 2-4 hours and ask a friend or relative if you need help with this.

If you have urine test sticks for ketones, called ‘Ketostix’, check your urine for ketones every 4 hours as well. Ketones are sometimes produced in the urine when you are very unwell or if you stop taking your insulin, which you should never do. A trace of ketones is quite common, but they should not show more than 1+ in normal circumstances. If they are strongly positive at 3+, that shows that your diabetes is getting worryingly out of control.
If your blood sugar stays high despite increasing your insulin, especially if your urine has ketones in it, and if you get abdominal pain, breathless or become drowsy and are vomiting, seek medical advice straight away. Go to your local hospital and call for an ambulance if needed.

Don’t just wait to see what happens next. Its best to get the problem checked and sorted out before it gets seriously out of hand.

What diet can I follow when unwell?

When you are ill, you may not feel like eating – but try to take something. Don’t stop you insulin because you can’t eat. If you can eat only small amounts choose simple, easy to digest foods such as soup, milk, puddings or cereals.

If you can only manage fluids, take frequent sips of sugary drinks such as lucozade, fruit juice, ordinary non-diet coke or lemonade. At the same time drink plenty of water to avoid dehydration- roughly a glass every hour.

How much extra insulin should I take when unwell?

If your blood sugar is less than 10mmols, take your usual insulin dose and keep a check your tests. Carry on checking your blood sugar every 2-4 hours until you are feeling better and are eating and drinking normally.

If your blood sugar is higher than 10mmols, then you need extra insulin. If your are unwell and the blood tests are between 10 and 15 mmol/l, take extra 4 units of fast acting insulin such as Actrapid, Novorapid, Humalog or Humulin S. If fast acting insulin is not available to you, use you usual insulin mixture. Check again after 2 hours and repeat if needed.

If your blood tests are between 15 and 20 mmol/l, take an extra 6 units of fast acting insulin or of your normal insulin mixture. Check again after 2 hours and repeat if needed.

If your blood tests are over 20 mmol/l, take an extra 6 units of fast acting insulin or of your normal insulin mixture. Check again after 2 hours and repeat if needed. However, you should also seek medical help, especially if the situation is the same after 2 hours or if you have ketones in the urine or any of the symptoms mentioned.

Seeking advice and what care to expect

You should be taught about how to deal with illness and about the “sick day rules” when you first get diabetes and this should be gone over with you if you change treatment – especially if you start insulin - or if you have had an illness which you found difficult to deal with. You should know all about blood testing and whether it is right for you to do ketone urine testing as well. You should know how to adjust your insulin treatment in this situation. You should expect to get prompt and clear advice if you are ill and your diabetes is out of control. If you come into hospital, you should expect to be seen by the specialist diabetes team of doctors and nurses as soon as possible. I you have had an illness and could not deal with it by yourself and needed medical help, someone should talk over with you what went wrong and how it could have been avoided. Be sure you what to do in the future.