The government has launched a campaign to help people identify the early signs of a stroke and encourage them to contact 999 if they suspect that somebody is having an attack.
A "FAST" test has being designed to gauge symptoms, including facial weakness, inability to raise both arms and whether somebody can speak or understand what is being said.
The adverts, which will feature on TV, radio, online and in print, will emphasis the need to act quickly to limit damage to the brain by stopping the symptoms "spreading like fire".
Studies show that patients who have their stroke confirmed by a scan quickly and are given access to clot-busting drugs have a higher chance of survival.
But only 42% of patients currently receive a brain scan within 24 hours of having a stroke to confirm diagnosis, and only 62% are treated on a dedicated stroke unit.
It is predicted that thousands of lives could be saved and 4,500 people could escape disability if they recieved attention immediately after a stroke.
Professor Roger Boyle, national director for heart disease and stroke, said: "For every minute of delay you can lose about 1,000 miles of nerve fibres in the brain. So for everybody, speed is of the essence."