Hypoglycaemia and Driving Guidelines

Definition of Hypoglycaemia-Mild and Severe

Mild Hypoglycaemia

A hypoglycaemia is a blood glucose of less than 4.0 mmol/l with or without symptoms. A mild hypo is when a person can recognise the early warning signs and self treat with 15g to 20g of quick acting carbohydrate. Early warning symptoms include sweating; shakiness; weakness; hunger; anxiety; tingling lips.


5-6 Dextro-energy tablets or LucozadeTM tablets


200ml LucozadeTM (Lucozade now has 50% less carbohydrate)


150ml-200ml Coke TM


150-200ml Fruit Juice

The person should be advised to check their blood glucose after 5-10 minutes to check that the blood glucose has been corrected to 4.0mmol/l or above. If it has not been corrected they should be advised to take another hypo treatment.

Severe Hypoglycaemia

A severe hypo is when a person needs help from a third party to treat hypoglycaemia or is too drowsy to swallow an oral treatment safely or is unconscious. Later warning symptoms include slurred speech; difficulty concentrating; confusion; aggression/irrational behaviour; loss of consciousness. In this instance, if the person is unconscious or too drowsy to swallow, they should be placed in the recovery position and Glucagon should be administered if available. The emergency services should also be called.

Hypoglycaemia and Alcohol

Alcohol increases the risk of hypoglycaemia overnight and into the next day. Patients should always be advised to have a carbohydrate snack before bed and never drink alcohol on an empty stomach.

Hypoglycaemia and Driving Guidelines

A patient who is on any hypo-inducing diabetes medication such as sulphonylureas-Diamicron MR; Diaglyc; Diabrezide; Gliclazide or insulin treated-Type 1 or Type 2 should carry out the following checks before driving. They should also inform their Motor Insurance Company and the National Driver Licence Service (NDLS) that they are on hypo-inducing medication. It should be documented in the patient's notes that they have been informed of this.

  • They should check their Blood Glucose (BG) before driving even if it is a short journey.
  • If the BG is 5.0mmol/L or less they should have a carbohydrate snack such as a banana or cereal bar.
  • If the BG is less than 4.0mmol/L they should treat the hypoglycaemia before driving-as above.
  • They should always carry a BG monitor with an up to date time function in the car and a hypoglycaemia treatment and carbohydrate snacks.
  • They should carry some identification with them stating what treatment for diabetes they are on.
  • If they feel symptomatic of a hypoglycaemia, they should pull in, take the keys out of the ignition, sit in the passenger seat and treat the hypo.They should wait at least 45 minutes until full cognition has returned before driving.

If you are starting a patient on a hypo-inducing agent, please refer to the
 NDLS Driving and Diabetes Guidelines.