New guidelines by the GMC will see doctors obliged to tell the DVLA if they think their patient is unfit to drive, which could include people with dementia.

If you’re diagnosed with dementia it means you need to let the Driver & Vehicle Licensing Agency (DVLA) know, although you may still be able to continue driving, so long as you are regularly assessed and can still drive safely.

However, new guidance from the General Medical Council (GMC) states that a doctor must contact the DVLA if they believe one of their patients is driving against medical advice.

As it stands, doctors do not need a patient’s consent to inform the DVLA, which is legally responsible for deciding whether a person is medically fit to drive, when a patient has continued driving in such instances.

Niall Dickson, the chief executive of the GMC, said: ‘This is difficult territory. Most patients will do the sensible thing but the truth is that a few will not and may not have the insight to realise that they are a risk to others behind the wheel of a car.’

‘A confidential medical service is a public good and trust is an essential part of the doctor-patient relationship. But confidentiality is not absolute and doctors can play an important part in keeping the wider public safe if a patient is not safe to drive.’

Dementia can affect your spatial awareness – the ability to judge distances between areas –and this can impact quite noticeably on your ability to work out safe distances while you’re driving. It can also affect your ability to make sense of road signs, remember routes and rules of the road, have quick enough reaction times to allow for stopping, starting and the actions of other drivers, and being able to read the road.

Steve Gooding, director of the RAC Foundation, said: ‘Thirty-seven million drivers depend on the car for getting about and for those with serious medical conditions there is a real fear around losing their licence.

‘The worst thing motorists can do is ignore medical advice. If they don’t tell the DVLA about something that impacts on their ability to drive safely, then their GP will.’

For tips on spotting the signs of unsafe driving, click here.