Sick Day Rules & Diabetes: What You Need To Know

Written By:
Cazzy Magennis
Last Updated:
May 2, 2021

Being sick with diabetes isn't fun, and it can be dangerous. But I've put together this guide on the sick day rules for diabetes that I follow when sick...

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When anyone gets sick, it’s not a great time but when someone with diabetes gets sick, it can be even more dangerous. 

This is because sickness tends to add stress to our bodies which will result in higher blood sugars. 

But don’t worry, there are sick day rules in place for those with diabetes that can help counteract this. 

I’m going to take you through all you need to know about sick day rules and type 1 diabetes. 

How does being sick affect your blood sugars? 

Any infection or illness (even stress) can raise your blood sugar levels. 

This is because when your body is trying to fight an illness or infection, it naturally releases more sugar (glucose) into your bloodstream. 

This is separate from glucose from food because it can happen even if you’re not eating at all, or eating less than you’re used too. 

When you don’t have diabetes, your body will just naturally produce more insulin to counteract the extra sugar, but unfortunately, we don’t have that luxury, so we need to give the extra ourselves. 

You know yourself when you feel sick with high blood sugars, it doesn't feel pleasant, so adding that to already feeling ill with an illness can wreak havoc on our bodies.

When you feel sick, are throwing up, or experiencing diarrhea, it can make your blood sugars drop because you’re not actually absorbing the food you’ve given insulin for.

This can make being sick with diabetes a little riskier, but don’t worry, there are things you can do to help this, and we will discuss them below. 

Dehydration and diabetes: how does it affect your blood sugars? 

Another thing to consider when you’re sick with diabetes is dehydration and how it impacts your blood glucose levels. Remember that dehydration can be caused by high blood sugars and vomiting and dehydration can further raise your blood sugars creating a somewhat vicious circle. So, it’s very important to keep drinking fluids regularly. 

What are the sick day rules for diabetes? 

These sick day rules will apply to both type 1 and type 2 diabetes unless otherwise indicated, and in the end, I will link you to an excellent resource that can help you calculate specifics for dealing with diabetes on sick days. 

1. Keep taking your insulin

Whether this is in the form of insulin injections, an insulin pump, or tablets for regulating your blood sugar (for type 2 diabetics). You mustn’t stop taking your insulin. If your body doesn’t have access to insulin (even if it feels like it’s not working!), you increase your risk of DKA and getting sick further (we will discuss this further below). So keep taking insulin, and try to keep eating little but often to help balance your insulin to food ratio. 

2. You may need more insulin

When your blood sugars are running higher, you typically end up needing “more” insulin to help bring them down, because your body is fighting an infection. 

If your blood sugars are 10 mmol or above, it’s typically recommended you give yourself 10% more of your daily dose, then check your blood sugars every 4 hours. If there is no improvement in 24 hours, then you should raise again to another 10%. 

If your blood sugars are 13 mmol or above, after 48 hours, then it’s recommended you increase your background insulin by 10%, and given an extra dose of fast-acting insulin (usually 10% of total daily insulin), and repeat every 2-4 hours. 

You should keep drinking 5 pints (2 liters) of water daily too. 

I’ve included the sheet of the NHS where these recommendations are based on. (Remember I am NOT a medical professional!) 

But I typically increase my insulin by around 10% when I’m running high with illness, but can sometimes reach 20% depending on the situation. 

Below is a useful table on how to work out 10% and 20% of total daily insulin amounts. 

insulin doses

3. Don’t panic 

As I’ve mentioned above, stress can cause our blood sugars to rise further, so being worried about being sick can make you sicker. It’s a stressful circle! 

But it’s important to stay calm, as this will help you keep yourself and your body under control. 

If you have no idea what you’re doing, then contact your diabetes team for advice. 

4. Test for ketones 

If you have type 1 diabetes-like me, then it’s super important that you test for ketones. Ketones can push you into DKA which is basically the non-safe zone for people with diabetes. 

DKA is short for Diabetic ketoacidosis and it is a serious complication of diabetes that occurs when your body produces high levels of blood acids called ketones. 

This occurs when your body isn’t getting access to insulin. 

It can lead to a coma situation, so it’s VERY important that you take ketones seriously, and do all you can to eliminate them.

If your blood sugar is 14 mmol (270 mg/dl) or above, for long periods, then you should test for ketones. You can get ketone testing sticks from any pharmacy, and they’re useful to have.

You just simply need to pee on the stick and it will indicate the level of ketones.

Sometimes a low level will indicate you’re getting sicker, and you can usually try and flush them out with lots (and I mean lots of water), but if your ketones are high then it’s time to get in touch with a medical professional. 

If you’re unsure about ketones, then it’s best to give your doctor a quick call if you’ve got a trace of any, just to keep yourself covered. 

Symptoms of ketoacidosis:

  • Blood sugar over 14 (270) 
  • Ketones in your urine 
  • Extreme thirst 
  • Peeing a lot 
  • Extreme tiredness 

Seek urgent help if you are vomiting alongside the above symptoms, rapid breathing, and you are drowsy. 

5. Stay hydrated

When you are ill, your body is naturally dehydrated because it’s being deprived of nutrients and if you’re being sick, then it’s going to be further deprived. Now, add into the mix of type 1 diabetes and the possibility of DKA, then there is a risk of your body becoming super dehydrated, which will just make you sicker. 

So, you must keep drinking water! This doesn't mean gushing lots of water down at once.

You need to keep drinking water throughout the day. Even if you just keep peeing it out (because your blood sugars are high), you need to keep drinking water and sugar-free drinks. 

6. Know when to get help 

When you’re newly diagnosed with diabetes, you’ll probably freak out the first time you experience being sick with diabetes, and honestly, that’s completely normal. 

Over time, you may find you’ll start being able to manage illness with diabetes at home, rather than seeking emergency help right away (unless you actually need to of course!). 

Never struggle alone, if you don’t think you’re on top of your management, then ask for help, there is no shame in that, and you could save your life! 

7. Test regularly 

When you’re sick with diabetes it can often be tempting to test your blood sugar every 15 minutes, especially if you’re on the Freestyle Libre or Dexcom, which makes it super easy to access your numbers, but sometimes there is such a thing as testing too much. 

You’ve got to give yourself and your body time to respond to treatment or insulin, so test and adjust every few hours (as we mentioned above), rather than every 15 minutes. 

When you’re testing your blood sugars when you’re sick, it’s really important to test via finger pricks and not a CGM or Freestyle Libre. (MiaoMiao).

This is because when you’re sick, these devices can become inaccurate, and you can't depend on them.

When sick, it’s important to revert to the traditional finger pricks for an accurate representation of your blood glucose levels. 

I’m definitely guilty of over-testing when I’m sick, but this is something I try to work on! 

Since I am naturally more clued up about type 1 diabetes and sick day rules, I thought it would be good to include a very useful resource for managing type 2 diabetes when you’re sick. A lot of the things mentioned above apply to all forms of diabetes management, but with some specific type 2 tablets and medications, there is extra advice. You can find out more here. 

All these tips I’ve given above are based on my own experience with sick day rules and diabetes. I am not a medical professional and as I’ve said above, you should seek medical advice when you’re sick or before you make major changes to your diabetes regime! 

But since these tips for sick day rules and diabetes have helped me successfully avoid any sort of hospital admission in 10 years, I figured it would be good to share! 

Managing your diabetes in hospital

If despite your best efforts, you do find yourself in hospital, then it’s important not to panic.

Because diabetes is such an individual disease, in the sense that no one formula will work for everyone, then it can often be daunting letting a new doctor or someone who doesn’t know you, look after your diabetes.

But you can help prepare for this by bringing everything you need to the hospital with you. 

This will include any information on the types of insulin you take, what time you typically take them etc. If you’re on an insulin pump, do not take your insulin pump off. Wear it to the hospital, and let your doctor know that you have an insulin pump on as this will require a specific response! 

I’ve put together a little packing list for the hospital trip to help ensure you don’t forget anything. 

hospital packing list

If you’ve got any other tips for managing diabetes when you’re sick, then simply drop a comment below and share with others. 

Other useful posts: 

Cazzy Magennis

Living with type 1 diabetes for over 10 years has given me a lot of life experience, challenges and opportunities. I’ve had ups and downs, but I’m proud that I can live out my dreams whilst managing t1d. I hope my stories can help your daily life with diabetes too!

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