The Road Safety Authority (RSA) says new guidelines on medical fitness to drive will be rolled out before the end of the year.
The RSA has launched a campaign to raise awareness among people with medical conditions about the affect their illness could have on their driving.
This is a relatively new area of research for the RSA.
But studies from Canada show that road collisions among people with a medical condition decreased by 45% in cases where people were given the right advice about their illness and the effect it has on their driving.
The most common conditions of concern are heart disease, stroke and dementia which mainly effect older drivers.
However people with diabetes and sleep apnea are also affected.
The RSA says with the right advice and medication people can continue to drive safely.
The new guidelines for car and motorbike drivers will be issued before the end of the year while guidelines for truck and bus drivers will follow by the middle of 2013.
Director of the National Office for Traffic Medicine at the Royal College of Physicians in Ireland is Professor Desmond O’Neill.
He says there are a number of illnesses that can cause problems but drivers should not be overly concerned about being taken off the road.