People who are suffering a stroke are too slow to dial 999 even if they recognise the signs of the potentially deadly condition, according to new research.
Every year 150,000 people in the UK have a stroke and if they receive clot-busting drugs within the first few hours their chances of a full recovery are much greater.
But a paper published in the PLOS One journal showed patients delayed calling the emergency services.
Researchers investigated the reason for people's reluctance and found fear and denial were factors, while others did not want to "make a fuss".
Contacting their family, friends or GP before ringing 999 delayed some stroke patients' journeys to hospital for treatment.
The findings from interviews at three acute stroke units in the North East showed some patients had knowledge of the condition from seeing it in TV shows and adverts.
The widely-publicised Act FAST campaign had raised awareness of stroke in some patients, but did not necessarily increase any sense of urgency, particularly if they experienced symptoms different from those highlighted in the campaign.
Symptoms highlighted in the Act FAST campaign were: drooping of one side of the face; inability to raise one or both arms and keep them there; or speech problems. One or more of these symptoms is present in nine out of 10 strokes.
Martin White, professor of public health at Newcastle University and lead author of the paper, said: "People need to know that you may get some or all of the symptoms, and maybe not in the same order.
"If you suspect yourself or someone else is having a stroke you should call 999 straight away so life-saving treatment can be given."
Co-researcher Joan Mackintosh, research associate at Newcastle University, said: "Every minute counts and delayed treatment means patients are more likely to lose their independence, with consequences for themselves and their carers.
"Even a slight delay, for example calling your GP instead of calling the emergency services straight away, can have a big effect.
"The message has to be, dial 999 if any of the symptoms of a stroke appear, even if it's not all of them."
Frank Billham, 71, from Wideopen, Newcastle, took part in the study.
The ex-police officer had a stroke three years ago and has made an almost complete recovery because of the swift treatment he received.
He said: "I didn't know what was happening, my arm and face started to feel tingly, but I just ignored it, I thought it would go away. And then I just flopped over.
"My wife found me and thought I was asleep but when she tried to rouse me I was slurring my words and not moving properly. Fortunately she called an ambulance and I got treatment within a couple of hours."
He has recovered so well he can enjoy bike rides, walks, playing table tennis and gardening.
He added: "It has been an amazing recovery, I can live an almost normal life now thanks to my wife and the people who treated me. I would just say to anyone get immediate help, I dread to think what my quality of life would have been like if I hadn't got help so quickly."