According to research published earlier in 2014 Obstructive Sleep Apnoea (OSA) affects 5% of the population, but is often undiagnosed. Obstructive sleep apnoea syndrome (OSAS) is a severe form of sleep apnoea which may lead to excessive daytime sleepiness. 400,000 people have been diagnosed and are being treated for the condition, it is believed that up to 1.4 million drivers have not been diagnosed and could be at risk of falling asleep at the wheel without knowing why. It has already been reported that sleepiness contributes to up to 20% of motorway accidents and the severity of an accident may be increased as the driver’s reactions are impaired. The RAC are campaigning for better awareness of the condition and the improved diagnostic and treatment facilities for those concerned they might have OSAS.  Studies have shown that once sufferers are successfully treated, they are no more likely to have road traffic accidents than anyone else. If in doubt see your Doctor. Advice from DVLA Driving with OSA If you have OSA without daytime sleepiness and it does not impair your driving, you can continue to drive and do not have to notify DVLA. Driving with OSAS You are legally obliged to tell DVLA if you have been diagnosed with OSAS or any sleepiness sufficient to impair your driving. On receipt of your correspondence DVLA’s Medical Group will send you a questionnaire. In the meantime, you are advised to stop driving until your condition has been successfully treated. Failure to advise DVLA of a medical condition is a criminal offence, and may affect the validity of your insurance cover. You must tell DVLA medical enquiries team at the point of diagnosis or recognition of any symptoms. Once your symptoms have been brought under control you should reapply using the relevant form found on DVLA medical pages.