Lives are being lost because of a "worrying" lack of awareness in the UK about strokes, campaigners say.
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A survey of 1,000 adults by NOP found a fifth failed to recognise the symptoms of a stroke.
Some 40% said they would not call an ambulance if they developed facial, arm and leg weakness and speech problems, the most common symptoms of stroke.
Campaigners estimate 25,000 people, of 67,000 annual deaths from strokes, die needlessly due to this ignorance.
When asked what they would do if they suspected a friend or relative was suffering a stroke, 33% said they would advise them to have a lie down, and 12% would wait to see if symptoms worsened before taking further action.
The poll found awareness of stroke varied between regions, with those in Yorkshire being the least well informed overall - 30% failed to recognise the symptoms of stroke, compared to 14% in East Anglia.
Joe Korner, of the Stroke Association, said: "These survey results show that much, much more investment is needed to raise awareness of stroke symptoms.
"As a charity we simply don't have the funds to do more than scratch the surface in terms of raising awareness.
"This lack of understanding is a real problem but we are convinced that our message would work with the right investment from the government."
Mr Korner added: "The fact that only 7% correctly identified stroke as a major burden on the NHS highlights the extent to which stroke is overshadowed by conditions such as heart disease and cancer.
"This must change - stroke is the third biggest killer in the UK and the biggest cause of severe disability. It affects people of all ages and can be prevented and treated."