Hypos and driving

These limitations might sound like they will take all the fun out of driving, but if you’re sensible about managing your blood glucose, the impact on your life should be minimal. Always bear the following guidelines in mind. 

Blood glucose monitoring and driving

Check your blood glucose regularly. Before, after and while you drive, your blood glucose level should always be above 5 mmol/L. 

If you’re driving for a long time, make sure you test your blood glucose at least every 2 hours. When you’re concentrating on driving, you might not notice any signs that your blood glucose is falling or rising – it’s always better to pull over and be safe. 

If you get stressed while driving, this could affect your blood glucose and cause it to go high or low. In addition, if you’re normally active, sitting in one place for a long time might cause your blood glucose to increase. There are many factors that might affect your blood glucose while driving – that’s why it’s so important to test regularly. 

Hypoglycaemia and driving

Keep hypo treatments and snacks in your car. You never know when you might get stuck in traffic or delayed due to roadworks. 

If your blood glucose is low, you may find it difficult to concentrate and your reactions will be slower than usual. This can really affect your driving and you may not even be aware of it. 

If you’re involved in an accident while you’re having a hypo, you won’t be covered by your insurance, and if you’re caught driving erratically, you may be charged with a driving offence. This will result in you having to pay for any damages and you may have your licence removed. 

What to do if you have a hypo whilst driving

If you’re driving and you have a hypo – defined by the DVLA as having a blood glucose level less than 4 mmol/L then you should:

• Pull the car over and stop your car in a safe location. 
• Take the keys out of the ignition and move over into the passenger seat. 
• Treat your hypo with fast-acting glucose, and test your blood glucose again. Eat a longer-acting carb snack too. 
• You must not drive again until your symptoms have gone and your blood glucose level has been more than 5 mmol/L for at least 45 minutes. 
• It takes this long for your brain to start working properly again. 
• Don’t be tempted to drive just because you feel OK – your brain function might still be slow and affect your concentration and reactions. 
• Afterwards, think about why you had a hypo and what you need to do the next time to prevent it. 

If there’s anything you’re unsure about, talk to your diabetes care team.  They can give you more help and information if you have any concerns about driving. You should also read the DVLA’s  guide to insulin treated diabetes and driving.