Diabetes & driving

You do not have to give up driving if you have diabetes, but as you are at increased risk of diabetes-related incidents, it does mean that you need to plan in advance before you get behind the wheel.

What are the concerns relating to diabetes and driving?

The main concern with driving when you have diabetes is the chance of hypoglycaemia (low blood glucose) while driving.

  • Hypoglycaemia occurs when the blood glucose level is less than 4 mmol/l, or where symptoms of hypoglycaemia are experienced at a level close to this.
  • Hypoglycaemia can be classified as mild, moderate or severe and needs to be reversed right away to prevent impact on the brain and risk of unconsciousness.
  • Even mild hypoglycaemia can impair your ability to drive safely.  
  • Very high blood sugar levels (hyperglycemia) can also cause you to feel unwell or
    tired, and may affect your ability to drive safely. You should not drive if you’re severely hyperglycaemic.

Other concerns related to diabetes and driving, that can affect your ability to drive safely are the possible complications of diabetes such as eye problems, loss of sensation in your feet or heart problems.

How to stay safe while driving

Avoid hypoglycaemia (situations where your blood sugar gets too low).

  • Have meals and snacks before long journeys, and take regular, short breaks from driving.
  • Check your blood sugar levels before you start a long journey and if your blood sugar is low, have a meal to avoid a fall in your blood glucose level during the drive.
  • Keep a supply of plain muesli bars, biscuits, glucose tablets dried fruit and long lasting fruit juice in your pocket or in the glove box.

What to do if your blood sugar gets too low while driving

Many of the accidents caused by hypoglycaemia are because drivers have continued to drive, ignoring their hypo warning signs (eg hunger, sweating, feeling faint). If you feel that your blood sugar is low while driving:

  • Stop the vehicle as soon as possible.
  • Switch off the engine, remove the keys from the ignition and move from the driver’s seat.
  • Take some fast-acting carbohydrate, such as glucose tablets or sweets, and some form of longer-acting carbohydrate.
  • Do not start driving until 45 minutes after blood glucose has returned normal. It may take up to an hour before your brain has time to recover.

Situations when you should not drive 

  • If your diabetes is newly diagnosed (you have been recently diagnosed), and your treatment is still being adjusted, you may not be fit to drive just yet. Check with your doctor.   
  • If you experience hypoglycaemia without warning signs (called hypoglycaemia unawareness), it may be unwise for you to drive. You should discuss this with your doctor or specialist diabetes nurse.
  • If you have a severe hypoglycaemic episode (eg when you need someone else’s help to deal with it), you shouldn’t drive for 24 hours. If you have several hypoglycaemic episodes, you should talk to your doctor before you return to driving.
  • If you have a severe hypoglycaemic episode while you’re driving, you shouldn’t drive for at least a month – whether you’re involved in a crash or not. It’s likely you’ll need to see a specialist before you can safely return to driving, and you’ll need to talk to your doctor.

Licence conditions

Sometimes a driver with diabetes may be issued with a licence that has certain conditions attached. The conditions will depend on:

  • the type of licence (classes and endorsements)
  • how the diabetes is controlled
  • whether the driver has any history of hypoglycaemic attacks
  • how carefully the driver follows their medication schedule
  • an assessment of the extent to which the driver suffers from the medical complications that are commonly associated with diabetes.

The Transport Agency decides the licence conditions, having regard to the Medical aspects of fitness to drive booklet, and in consultation with the Transport Agency's Chief Medical Advisor.

Learn more

Diabetes and driving Factsheet 16, November 2013 NZ Transport Agency